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Building My Linux Box…The Implementation

Ubuntu 13.04 Raring Ringtail
In an earlier post, I outlined my plan for building a Linux Box.  Here I will post how that plan was ultimately implemented. Life has taught me that all good planning is ultimately undone, and at some point, you must improvise.  That has also proven true for this quest to up grade my computation.  Specifically:

    • After ordering all the hardware, it came to me that it was dumb to attempt to reuse my old semi-reliable, slow CD drive.  So I purchase the HP 24X Multiformat DVD/CD Writer (dvd1260i) at Best Buy for $40.
    • I discovered that the my old PC had ATA hard drives (commonly called an IDE drive) and my new Mobo only supports SATA (SATA 3Gb/s & 6GB/s and it includes an external eSATA port).   This blows my plan to reuse my existing hard drives … stupid me, I should have checked.  I did a quick scan for ATA controller cards and found a few (not many) for $15 to $30.  I could buy the card and make this work but it doesn’t seem like a good investment.  The drives are 400G drives and has a maximum data transfer rate of about 133MB/s (i.e. ATA/66).  The maximum data transfer rates of SATA II and SATA III are 300 MB/s and 600 MB/s, respectively.  I can buy a Seagate – Barracuda 500GB SATA II Internal Hard Drive for $70.  Given my objective to increase the performance of my computing experience, buying a new SATA III hard drive should have been part of the original plan.
    • After reading up on RAID and the Intel Rapid Storage Technology (RST), I concluded that it would be best to do a Software Raid and not use RST.
    • While I assumed in my original plan that I would dual boot the box with Linux and MS Windows, the comment from armahillo convinced me of what I suspected I should do; and that was to make winemono, and PlayOnLinux work for me.  While I haven’t stressed them, so far so good.  I have not installed VirtualBox and I suspect I will not … unless I get desperate.
    • I was planning to reuse my old keyboard and mouse, but you know, I hated that keyboard and the mouse was already acting badly and about to die on me.  So I ended up replacing them with sometime worthy of my new system.

Configuring Ubuntu

You’ll find many recommendations on how to jazz up a newlly install Ubuntu system.  I found some of these suggestions useful:

Installing “dot” Files

Like may, over the years I have made a large time investment in tuning my .bashrc, .vimrc, and other such resource files.  I installed my beloved “dot” files from my Git repository.

Installing Google Chrome’s Native PDF Reader in Chromium

Chromium is a fully open-source version of Google’s Chrome, and for licensing reasons, it doesn’t come packaged with the integrated Flash or a native PDF reader.  Lucky, there is a work around and that is documented here: Use Google Chrome’s Native PDF reader in Chromium.

Installing My Squeeze Box

I have a SqueezeBox device in my workshop for playing music.  On my old PC, I had installed the SlimServer which would provide the music stream.  I want to now reestablish that capability on the Linux box. The post How to Use Squeezebox With Ubuntu and the Logitech SqueezeBox Wiki gives you all the information you should need.

The Ubuntu (Debian) software for the SqueezeCenter or now called the Logitech Media Server (formerly known as SlimServer) is maintained by Logitech, and therefore, will not be installed via get-apt.  To make it part of the package resource list (used to locate archives of the package distribution system in use on the system), you need to update the sources.list file.  To do this, do the following:

sudo vim /etc/apt/sources.list

Scroll to the bottom of the file and enter the following information and then save:

## This software is not part of Ubuntu, but is offered by Logitech for the Logitech Media Server (formerly known as SqueezeCenter or SlimServer).
deb http://debian.slimdevices.com stable main

Now do the following:

sudo apt-get remove --purge logitechmediaserver
sudo apt-get update
sudo apt-get install logitechmediaserver

Now open a browser and type “http://desktop:9000” as the URL, where “desktop” is the name of your Linux system.  This brings you to a Squeezebox interface to configure the system.

If you want to start/stop Logitech Media Server manually you can run:

sudo /etc/init.d/logitechmediaserver stop
and
sudo /etc/init.d/logitechmediaserver start

Setting-Up Harmony Remote

I have the Logitech Harmony 650 Universal Remote Control for my home theater system.  To program the device, it must be tethered to a web site via a Windows or Mac PC.  The Harmony web site does reference some Linux support done by others.  The posting “How to set up a Harmony remote using Linux” and “Logitech Harmony Universal Remote Linux Software Support” give you the basics of what you need to do.  Within these sites you lean about the utilities concordance and congruity. The first utility provides most of the functionality of the Windows software provided by Logitech and the second is a GUI application for programming Logitech Harmony remote using concordance.  To install these utilities, do the following:

sudo apt-get install concordance
sudo apt-get install congruity

You also have to configure the web browser to ask what to do with download links. It is best to use Firefox and you can configure downloads via: Edit->Preferences->General->Downloads->Always ask me where to save files.

Now plug the remote into the PC using the provided cable, and enter the command: sudo concordance -i -v.  You should get a bunch of data and the word “Success”, verifying that you can talk to the device.

Now go through the following process:

    1. Plug in the remote via the provided USB cable.
    2. Visit the Harmony Remote’s member site URL.  This appears to be a legacy support site and Logitech site listed in the documentation with the device will not work under Linux.
    3. Create an account or login into your existing account.
    4. Skip/ignore the “you need to update your software” steps, and eventually a download prompt appears.
    5. Choosing ‘open’ rather than ‘save’ impressively results in the Congruity graphical setup up launching.
    6. Step through the setup boxes as prompted.

Setting-Up Keyboard & Mouse

Logitech Wireless Illuminated Keyboard K800 To improve my driving experience, I purchased the
Logitech Wireless Illuminated Keyboard K800and the Logitech M510 Wireless MouseLogitech M510 Wireless Mouse.  These devices use the Logitech Unifying wireless technology, which allows a single wireless receiver to connect with multiple Unifying devices.  I plugged in the mouse’s receiver  and in short order the mouse was working.  I was a bit concerned about the ability of the receiver to support multiple device (i.e. the keyboard) simultaneously under Linux.  Doing a quick search I found a post discussing how to do the device pairing under Linux.  To install the ltunify pairing software, and do the pairing, do the following:

cd ~/src
git clone https://git.lekensteyn.nl/ltunify.git
cd ltunify
make install-home

To list the devices that are paired: sudo ltunify list
To pair a device: sudo ltunify pair, then turn your wireless device off and on to start pairing.
To unpair a device: sudo ltunify unpair mouse
To get help: sudo ltunity --help

Mouse Xbindkeys

The M510 mouse has extra buttons on its left side and the scroll wheel  has a side-to-side click, but out of the box,the don’t do anything under Linux.  It would be nice to make use of these extra buttons.  To address this problem, I found pointers in these posts: How to get all those extra mouse buttons to workHow do I remap certain keys,  Mouse shortcuts with xbindkeys, and Guide for setup Performance MX mouse on Linux (with KDE).

Basically, using Xbindkeys, I want to map the mouse buttons with desired actions. I want to setup the M510 mouse extra buttons as follows:

    • Left-side Buttonup mapped to Page Up and down mapped to Page Down
    • Scroll Wheelmove left mapped to Copy and move right mapped to Paste
    • Scroll Wheelpress mapped to Paste

xev prints the contents of X events by creating a window and then asks the X Server to send it events whenever anything happens to the window.  It’s sort of a keyboard and mouse events sniffer.  If we know what event name the X Server gives to our buttons, then we can remap them. Using this program, we find out the following:

    • Left-side Buttonup is known by the X Server as button 9
    • Left-side Buttondown is known by the X Server as button 8
    • Scroll Wheelmove left is known by the X Server as button 6
    • Scroll Wheelmove right is known by the X Server as button 7
    • Scroll Wheelpress is known by the X Server as button 2

Now we need a mechanism to re-map mouse (or keyboard) button inputs.  Xbindkeys is is a X Windows program that enables us to bind commands to certain keys or key combinations on the keyboard and it will also work for the mouse.  The file  ~/.xbindkeysrc is what xbindkeys uses as a configuration file to link a command to a key/button on your keyboard/mouse.  There is also xbindkeys_config is an easy to use gtk program for configuring xbindkeys. To install these tools, do the following:

sudo apt-get install xautomation xbindkeys xbindkeys-config

To create your initial xbindkeys configuration file, just run the following command:

xbindkeys --defaults > $HOME/.xbindkeysrc

The syntax of the contents of .xbindskesrc is simple and is illustrated below:

# short comment
    "command to start"
        associated key

The "command to start" is simply a shell command (that you can run from a terminal),  and "associated key" is the key or button.

Now, using an editor, update the .xbindkeysrc file to include the following:

# Do a Page Down when mouse left-side down button is pressed
"xte 'key Page_Down'"
    b:8
# Do a Page Up when mouse left-side up button is pressed
"xte 'key Page_Up'"
    b:9
# Move scroll wheel to the left to copy text
"xte 'keydown Control_L' 'keydown Shift_L' 'key c' 'keyup Control_L' 'keyup Shift_L'"
    b:6
# Move scroll wheel to the right to paste text
"xte 'keydown Control_L' 'keydown Shift_L' 'key v' 'keyup Control_L' 'keyup Shift_L'"
    b:7
# Press scroll wheel to paste text
"xte 'keydown Control_L' 'keydown Shift_L' 'key v' 'keyup Control_L' 'keyup Shift_L'"
    b:2

To activate any modification of the .xbindkeysrc configuration file, your have to restart xbindkeys.   This can be done via:

pkill xbindkeys
xbindkeys

Other useful resources are:

    • xte is a program that generates fake input using the XTest extension
    • xvkbd is a virtual (graphical) keyboard program for X Window System which provides facility to enter characters onto other X clients by clicking on a keyboard displayed on the screen.
    • xbindkeys_show is a program to show the grabbing keys used in xbindkeys
    • xmodmap is a utility for modifying keymaps and pointer button mappings in Xorg.

Moving from SplashID to KeePass

I have been using the MS Windows based SplashID to store passwords, credit cards, account numbers, etc. securely on my PC and cell phone.  I got it to work under Wine but I’m considering Linux alternatives.  I’m growing tired of purchasing SplashID licenses and the user interface looks like it was designed in the 1970’s.  I came across “Five Best Password Managers” which gave me the incentive to check out KeePass.  KeePass is a cross platform, open source password manager.  It is extendable via its plugin framework, where additional functionality can be added.  It looks like I can use Dropbox and KeePassDroid to get the data on my cell phone.  I found these sites useful to get the job done:

The first step was to get KeePass installed in Ubuntu.  I found it on the Ubuntu Software Center or you can use:

sudo apt-get install keepass2 keepass2-doc

I then exported the contents of my SplashID database to a CSV file and imported it into keepass2.  I set up the KeePass2 database within my Dropbox folder.  This way, it can be scych’ed with my cell phone. I then installed KeePassDroid on my cell phone, pointing it at the database with the cell phones Dropbox.  KeePassDroid is a port of the KeePass password safe for the Android platform.

There is some cleanup of the fields within the KeePass2 database, but the data is now accessable on both my PC and my cell phone.

Installing Wine

Wine allows you to run many Windows programs on Linux. Instead of simulating internal Windows logic like a virtual machine or emulator, Wine translates Windows API calls into Linux calls.  I used the following to install Wine:

sudo add-apt-repository ppa:ubuntu-wine/ppa
sudo apt-get update
sudo apt-get install wine

Using Wine on Windows programs can be as simple  or complex, it all depends on the program.  Ubuntu provides some guidance on how to use Wine, also check out Wine Documentation and Wine HowTo.

As of this writing of the post, the only thing I loaded via Wine was SplashID, which worked without any challenges.

Installing PlayOnLinux

PlayOnLinux is based on Wine, and so profits from all its features, yet it keeps the user from having to deal with all its complexity.  I also install this package, in part because it comes pre-configured to load some popular tools.  I used it to install Internet Explore (sometimes its the only browser you can get to work on a site), and Kindle.

Installing RAID

RAID is an acronym for Redundant Array of Independent Disks and RAID as the first tier in your data protection strategy. It uses multiple hard disks storing the same data to protect against some degree of physical disk failure. The amount of protection it affords depends upon the type of RAID used.  I’m not going to go into all the types of RAID, nor their benefits, but you can find much of this information, and much more, in the following links:

In my case, I had an existing disk drive (non-RAID), loaded with data, and I wanted to add an additional drive to make it a RAID.  This presents some challenges since you’re attempting to preserve the data.  In this regard, I found the following links helpful:

I had already installed one SSD and one HHD disk drives in my system.  I then installed a third drive that matched the HHD drive.  My 128GB SSD has the device name of /dev/sda1 and mounted as /boot.  The currently installed 1TB SATA HDD has the device name of /dev/sdb1 and mounted as /home.  The newly install 1TB SATA HDD has the device name of /dev/sdc.

Description of the procedures I used to create the RAID is as follows:

    • Physically install the additional hard drive.
    • Install mdadm, which is the Linux utility used to manage software RAID devices.

sudo apt-get install mdadm

    • Partition the newly installed disk. Use the following inputs: n to establish a logic partition, p to make it a primary partition, 1  should be the partition number, use the same sectors as the currently installed drive, t to set the partition type, fd hex code type, p to print what the partition table will look like, w to write all of the changes to disk.

sudo fdisk /dev/sdc

    • Create a single-disk RAID-1 array (aka degraded array) with the existing hard drive. (Note the “missing” keyword is specified as one of the devices. We are going to fill this missing device later with the new drive.)

sudo mdadm --create /dev/md0 --level=1 --raid-devices=2 missing /dev/sdc1

    • At this point, if you do a sudo fdisk -l | grep '^Disk', you see a new disk, that being /dev/md0.  This is the RAID but not yet fully created.
    • Make the file system (ext3 type like the currently installed hard drive) on the RAID device.

sudo mkfs -t ext3 -j -L RAID-ONE /dev/md0

    • Make a mount point for the RAID and mount the device.

sudo mkdir /mnt/raid1
sudo mount /dev/md0 /mnt/raid1

    • Copy over the files form the original hard drive to the new hard drive using rsync.

sudo rsync -avxHAXS --delete --progress /home/* /mnt/raid1

    • Just  in case of a disaster, copy the original hard drive to the SSD /dev/sda1 root file system as /home_backup.

sudo rsync -avxHAXS --delete --progress /home /home_backup

    • After the copy, to see the status of the RAID, use the command sudo mdadm --detail /dev/md0.  What you see is that the /dev/sdc1 drives is in “active sync ” state but no reference to the other drive.  When you do cat /proc/mdstat you see “md0 : active raid1 sdc1[1]” but again no reference to the other drive.
    • Edit your /etc/fstab file and edit all references of /dev/sdb1 to /dev/md0 and reboot the system.  With this, /dev/md0 will be used as /home on the next boot. This will free up the existing hard drive so it can be made ready for the RAID.
    • With fdisk, re-partition /dev/sdb1 with a partition of type fd. Use the following inputs: n to establish a logic partition, p to make it a primary partition, 1  should be the partition number, use the same sectors as the currently installed drive, t to set the partition type, fd hex code type, p to print what the partition table will look like, w to write all of the changes to disk.

sudo fdisk /dev/sdb1

    • Add /dev/sdb1 to your existing RAID array.

mdadm /dev/md0 --add /dev/sdb1

    • The RAID array will now start to rebuild so that the two drives have the same data. Use the following command to check the status of the rebuild.

sudo mdadm -D /dev/md0

    • For Ubuntu, it seems it is also necessary to update the /etc/mdadm/mdadm.conf file. If this is not done, the RAID device will not be mounted when you reboot the system. The solution is to run the following command on your system, once the RAID drive has been configured:

sudo cp /etc/mdadm/mdadm.conf /etc/mdadm/mdadm.conf_backup
sudo mdadm --detail --scan >> /etc/mdadm/mdadm.conf

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Linux Reboot … or … My System is Frozen and I Can’t Get Up!

sysrq-keyWhile I was building the environment for my Linux box,  I ran into some problems with Ubuntu.  I found myself with frozen screens or booted up into blank screens and other such things.  Seems that Ubuntu 13.04 is currently a bit unstable or I just screwed things up badly … a little of both I suspect. I managed to get through these problems, but too often I got desperate and I hitting the on/off switch to get the box rebooted.  Doing this can result in corrupted files and other such nasty things.  So this motivated me to research the “correct” way to get out of these Linux near death experiences.

The golden nugget here is actually at the end of this posting, that is the Magic SysRq Key.  This gem can get you out of most any freeze but I provide more here since the alternatives might be less intrusive.

Stopping a Running Process

While this post’s focus is on how to reboot Linux, keep in mind that sometimes the problem that your attempting to solve may be handled via a simpler approach.  Specifically, maybe you just need to kill a running process.

In the Bash shell, you can use job control:

    • Ctrl+C – halts the current command
    • Ctrl+Z – stops the current command, resume with fg in the foreground or bg in the background
    • Ctrl+D – log out of current session, similar to exit

On a Desktop version of Linux, there are normally six text consoles sessions available and one graphics session.  You could leave a frozen GUI, and go to a console screen to kill an offending process:

    • You can access the consoles by pressing CTRL + ALT + Fx (where Fx is a function key on the keyboard from F1 to F6).
    • Once you enter one of the consoles, you will be prompted for user name and password. Enter them and then you’ll reach a command prompt.  Now you can kill the offending process using the kill command.
    • To switch back to the graphic session, just click CTRL + ALT + F7.

The process “killing” could be done via the recommended kill -SIGTERM pid  or the more forceful kill -SIGKILL pid. There are also versions of these tools, killall and pkill, that use the name of the process as an argument instead of the process ID.

xkill is a utility for forcing the X server to close connections to clients. Closing an X application that has become unresponsive, or misbehaving in general. Execute xkill, and once it’s running, you simply click on the window you wish to  kill, and it performs a kill -9.

When Kill -9 Does Not Work

You are supposed to be able to kill any process with kill -9 pid, but you may come across a process that just will not die. Usually this happens when you are trying to kill a zombie process or defunct process. These are processes that are dead and have exited, but they remain as zombies in the process list. The kernel keeps them in the process list until the parent process retrieves the exit status code by calling the wait() system call. This does not usually happen with daemon processes because they detach themselves from their parent process and are adopted by the init process (PID=1) which will automatically call wait() to clear them out of the process list.

You may sometimes see the daemon defunct PID in the process list for a brief moment before it gets cleaned up by the init process. You don’t have to worry about these. You can also end up with an unkillable process if a process is stuck waiting for the kernel to finish something. This usually happens when the kernel is waiting for I/O. Where you see this most often is with network filesystems such as NFS and SaMBa that have disconnected uncleanly. This also happens when a drive fails or if someone unplugs a cable to a mounted drive. If the device had a memmapped file or was used for swap then you may be really screwed. Any kernel calls that flush IO may hang forever waiting for the device to respond.

Zombies can be identified in the output from the process status command ps by the presence of a “Z” in the “STAT” column. Zombies that exist for more than a short period of time typically indicate a bug in the parent program, or just an uncommon decision to reap children.  A zombie process is not the same as an orphan process. An orphan process is a process that is still executing, but whose parent has died. They do not become zombie processes; instead, they are adopted by init (process ID 1), which waits on its children.

Standard Reboot Commands

The vast majority of your systm shut downs or reboots will follow one of these two forms.  The first will halt the system so you can power it off and the second will reboot the system:

shutdown -h now
shutdown -r now

shutdown is the preferred and the safest ways to stop Linux. Never the less, in the tradition of Unix, Linux gives you more than one  way to accomplish this task.   reboot, halt, and poweroff are some additional commands that Linux provides to stop the system.  These commands can be more “forceful” than shutdown but similar to it.

The simplicity of these commands give the illusion that the system state of Linux is running or not running.  It isn’t quite that simple.  Linux can operate in several states called runlevels.

Linux Runlevels

A runlevel is a preset operating state for the Linux operating system.  A system can be booted into  any of several runlevels, each of which is represented by a single digit integer. Each runlevel designates a different system configuration and allows access to a different combination of processes and system resources.

Seven runlevels are supported in the standard Linux kernel. They are:

    • 0 – System Halted:  all system activity is stopped, the system can be safely powered down
    • 1 – Single User:  single superuser is the only active login and no daemons (services) are started. It is mainly used for maintenance.
    • 2 – Multiple Users: multiple users allowed but network filesystem (HFS) is not.
    • 3 – Multiple Users:  multiple users are allowed command line (i.e., all-text mode); the standard runlevel for most servers
    • 4 – User-Definable
    • 5 – Multiple Users: multiple users are allowed graphical user interface; the standard runlevel for most desktop systems
    • 6 – Reboot: just like run level 0 except a reboot is issued, used when restarting the system

In the interests of completeness, there is also a runlevel ‘S’ that the system uses on it’s way to another runlevel. Read the man page for the init command for more information, but you can safely skip this for all practical purposes.

By default Linux boots either to runlevel 3 or to runlevel 5. The former permits the system to run all services except for a GUI. The latter allows all services including a GUI.

Booting into a different runlevel can help solve certain problems. For example, if a change made in the X Window System configuration on a machine that has been set up to boot into a GUI has rendered the system unusable, it is possible to temporarily boot into a console (i.e., all-text mode) runlevel (i.e., runlevels 3 or 1) in order to repair the error and then reboot into the GUI.  Likewise, if a machine will not boot due to a damaged configuration file or will not allow logging-in because of a corrupted /etc/passwd file  or because of a forgotten password, the problem can solved by first booting into single-user mode (i.e. runlevel 1).

There are two commands for directly reading or manipulating the Linux rumlevels:

    • runlevel – Use the runlevel command to tell you two things: The last run level, and the current run level.  If the first character is ‘N’, it stands for none, meaning there has been no run level change since powering up.
    • telinit – The program responsible for altering the runlevel is init, and it can be called using the telinit command.

The topic of runlevels is actually much richer than what is illustrated here.  It plays a key role in Linux background processes, called services or daemons.  For more, check out this Managing Services in Ubuntu, Part I: An Introduction to Runlevels and Part II.

Getting a Login From a Frozen GUI Screen

A not so common problem is when a frozen, full screen X application takes control over your mouse and keyboard and it seems that the only way to regain access to the system is to force a shutdown.  The fact is, if you could get to a some form of terminal session, you might be able to kill the offending process and get out of this frozen state.  This is where accessing a console screen by pressing CTRL + ALT + Fx (where Fx is a function key on the keyboard from F1 to F6) can be very handy.

The X Server can often be the source of these frozen screen situations, so restarting the X Server may be the solution.  This can be done via the key combination Ctrl+Alt+Backspace.  Keep in mind that you will loses any unsaved data in applications.  Also, this capability is turned off by default on may Linux systems (including Ubuntu).  This was done to avoid confusion by  people accustom to MS Windows.  An alternative key combination is as follows:

Press AltGR + SysRQ + K instead (AltGR is the RIGHT ALT button and SysRQ is labelled “Print Screen” most of the times, and remember to press and hold the keys in the in the right sequence, e.g. starting with ALtGR, and ending with the K(ill) key).

You can turn back on the Ctrl+Alt+Backspace by following the instructions here.

Magic SysRq Key

If the system is completely locks up, or your filesystem fails, there are still alternatives. The “magic SysRq key” provides a way to send commands directly to the kernel through the /proc filesystem. It is enabled via a kernel compile time option, CONFIG_MAGIC_SYSRQ, which seems to be standard on most distributions.The magic SysRq key (or PrintScrn or Print Screen on some keyboards) is a key combination understood by the Linux kernel, which allows the user to perform various low-level commands regardless of the system’s state. This is a surprising feature of the kernel but is commonly used to perform a safe reboot of a locked-up Linux computer.  See this post for some historical perspective of the SysReq key.

To check if the CONFIG_MAGIC_SYSRQ option is enable on your Linux kernel, check the configuration file that installed to /boot partition.  Do this via:

cat /boot/config-$(uname -r) | grep CONFIG_MAGIC_SYSRQ

If your get “CONFIG_MAGIC_SYSRQ=y", then its enabled on your kernel.

When running a kernel with SysRq compiled in, /proc/sys/kernel/sysrq controls the functions allowed to be invoked via the SysRq key.  If the file contains “1“, that means that every possible SysRq request is allowed. See here for more on the /proc/sys/kernel/sysrq.

To actually reboot the machine there is a well know key sequence to follow: REISUB (or REISUO if you want to turn off the system instead of reboot).  Basically, if you keep pressed ALT + SysRq + R and then while you keep pressed ALT + SysRq you press E, I, S, U, B with about 1 second between each letter (do not type it fast). Your system will reboot. This  is a safer alternative to just cold rebooting the computer.

Mnemonic for REISUB is Reboot Even If  System Utterly Broken, and the keys pressed do the following:

R – Switch to XLATE mode
E – Send Terminate signal to all processes except for init
I – Send Kill signal to all processes except for init
SSync all mounted filesystems
U – Remount filesystems as read-only
B – Reboot

The magic SysRq key supports more then just the REISUB keys.  To see the larger range of thing you can do via Magic SysRq Key’s direct communications with the kernel, check out here.

Building My Linux Box…The Plan

I concluded it was time to retire my current PC (a Dell Dimension XPS 400, Intel Pentium D 820, 2.8GHz w/Dual Core Technology, 2G of memory, purchased in January 2006 for  ~ $2,500) and replace it with something better, aka faster.  It’s performing poorly, but most of all, I want to do some experimenting with iPythonmatplotlib, as well as, GNU Radio & digital signal processing.  To do this justice, I need a faster box and ideally loaded with Linux and X Windows.

I also think its time for me to build my own box, instead of purchase it already packaged and assembled.  They say you get more for your dollar, or at least you can invest the same money into things that will make a better system (instead of some more crappy speakers, mice, keyboards, etc.).  Given I’m building it, I want to pay special attention to getting the performance up.  I don’t need the top of the line CPU (I don’t believe you get sufficient value for your money), but I would invest in improving the predominate enemy of computer performance, that is I/O.  Also, I want the graphics to be fast and smooth.  The work on matplotlib and signal processing is likely to be graphically intensive.  I’m not going to be playing games on the system, but I’m going to keep an eye on the gaming communities hardware preferences.   I’m willing to go with a good (but not super, and therefore expensive) graphics board.

A fancy sound system isn’t a priority for me.  While my interest in GNU Radio & digital signal processing may have some use for a good sound system, I think I could live with the integrated sound system that will come on the motherboard.  Like graphics, if  it proves unacceptable, I’ll make the investment on another occasion.

Since I’m buying components and assembling it, I want to do some cherry picking.  When a vendor sells you an assembled box, they are often using cheaper / less functional components to save them cost.  I’m picking an Intel Core i5 CPU (I believe it has the best value for me).  Also, I’m going to get a -K Series Intel CPU and motherboard designed for overclocking and provide optimal performance for gamers and high-power users.  While I’m not doing gaming, I like the option to tuning the hardware and I have found the -K Series to be only slightly more expensive.  For a small amount of additional cash, I get some cool capabilities.

To get the better I/O that I want, I’m going to purchase one solid-state drive (SSD) from which I plan to boot Linux.  SSD’s are very much more expensive byte-for-byte when compared to a standard hard drive but boy they can fly!  Faster CPU and faster drives are my most valuable investment.  With the  financial investment in the SSD, I’m not going to purchase new hard drives but reuse the ones I have in my current PC (I’ll need them since the SSD I can budget for will not be large).  They are newer then the original Dell box, and besides  the hard drive has over 6 years of stuff on it, including a MS Windows environment that I have grown dependent on.  That brings me to the next point.

I want to dual boot the system with both MS Windows and Linux.  The Linux will be on the SSD, and it is here that I plan to spend much of my time.  I want to pick a Linux distribution that is well supported, popular, and a good graphic desktop environment.   I grew up on the Linux command line (then it was Unix) and I feel at home there, but I would like to try out the X Windows desktop.  If at all possible  I want the MS Windows to boot from my current hard drive.  I don’t want to have to reload software or copy an image … you never can get it to be the same again.  If I must, I’ll make the MS windows drive the default boot as it is now (and Microsoft seems to insist on being default).  If I can do this, moving into my new PC will be painless.

With my objectives and priorities fully articulated, lets explore what I intend to build.

Central Processing Unit (CPU)

For my CPU I have picked the Intel Core i5-3570K Ivy Bridge 3.4GHz (3.8GHz Turbo Boost and 6M Cache) LGA 1155 77W Quad-Core Desktop Processor which includes Virtualization Technology (VT-x), and Intel HD Graphics 4000.  What a mouth full …. here is what this all means:
intel core i5 3570k with stock cooler

    • Intel Core – Intel Core (sometimes refereed to as Core 2) is a brand name that Intel uses for various mid-range to high-end consumer and business microprocessors. In general, processors sold as Core are more powerful variants of the same processors marketed as entry-level Celeron and Pentium. Similarly, identical or more capable versions of Core processors are also sold as Xeon processors for the server and workstation market.
    • i5-3570K – The very first question after you concluded that your going with the Intel Core line, is Core i3 vs. i5 vs. i7 – Which one is right for me?   I’m driven to the i5 since the current Intel Core i5 models are generally considered the best price/performance choice for a gaming system and the i7  do NOT have built-in graphics capability (this would force me to buy a graphics card). Why K versions you ask? Well, the default Ivy Bridge processors are much harder to overclock, where the K series are unlocked and come with tools for overclocking.  This processor has overclocked test results running at a stable 4.7GHz.
    • Ivy Bridge –  Ivy Bridge is the latest generation of processors within the Intel Tick-Tock Development Model.   Intel introduced its Sandy Bridge desktop and laptop processors at the start of 2011 as there new micro-architecture …the tock.  Intel introduced Ivy Bridge in April 2012 new processor technology … the tick.  There is a school of thought that says you shouldn’t buy the last generation CPU because you can get more value (aka performance/dollar) from the previous generation.  But the prices I have seen and the comparative reviews have given me the courage to go with the latest generation.  Also check out this review with a description of Ivy Bridge.
    • Turbo Boost – This feature increases performance of both multi-threaded and single-threaded workloads.  Intel Turbo Boost Technology 2.0 allows the processor core to opportunistically and automatically run faster than its rated operating frequency/graphic render clock if it is operating below power, temperature, and current limits. It can boost the frequency up to 3.8GHz.
    • 6M Cache – This refers to cache used by the central processing unit of a computer to reduce the average time to access memory. The cache is a smaller, faster memory which stores copies of the data from the most frequently used main memory locations.  It comes it three types: L1, L2, and L3. L1 cache (sometimes called primary cashe) is the fastest cache and it usually comes within the processor chip itself.  L2 cache comes between L1 and RAM (processor-L1-L2-RAM) and is bigger than the primary cache. The L1 and L2 cache is per core but the last-level cache (L3), is shared among all cores and sometimes call Smart Cache since cache can be dynamically assigned to a core as it needs it. The “6M” refers to the number of bytes of data that the L3 cache can hold.
    • LGA 1155 – LGA 1155, also called Socket H2, is an Intel microprocessor compatible 1155 pin socket which supports Intel Sandy Bridge and Ivy Bridge microprocessors.
    • 77W – This is the  Thermal Design Power (TDP) is the maximum power consumed by the CPU under normal / regular use. In other words, the TDP is the max power a device will dissipate when running real applications. What’s more the TDP is given for graphics card default clocks.  TDP is a manufacturer’s data, and thanks to this information, CPUcooler manufactures can size their CPU coolers.
    • Quad-Core Desktop Processor – This is a multi-core processor (in fact a quad or 4 core)  computing component with four independent actual central processing units (called “cores”).  Intel manufacturers the four cores onto a single integrated circuit die (known as a chip multiprocessor or CMP), or onto multiple dies in a single chip package.  The proximity of multiple CPU cores on the same die allows it to operation at a much higher clock-rate than is possible if the signals have to travel off-chip.
    • Virtualization Technology – VT-x  (i.e. x86 virtualization or Vanderpool) is the facility that allows multiple operating systems to simultaneously share x86 processor resources in a safe and efficient manner, a facility generically known as hardware virtualization. With virtualization, you can have several operating systems running in parallel, each one with several programs running.  Each operating system runs on a “virtual machine”, i.e. each operating system thinks it is running on a completely independent computer. Note that on the Intel Core technology, the virtual machines are not assigned specific CPUs among the multiple CPUs but are shared by all.
    • Intel HD Graphics 4000 – Before the introduction of Intel HD Graphics, Intel integrated graphics were built into the motherboard’s northbridge.  HD Graphics 4000 is Intel’s 3rd generation of this integrated GPU technology.  The HD 4000 was completely redesigned and offers many improvement. The IPC (instructions per clock) can therefore be even 2x as fast  and overall up to 60% more performance should be possible.

One highly desirable feature missing from the Intel i5 line is Hyper-Threading Technology.  Hyper-Threading (HT) is a means for improving processor performance by supporting the execution of multiple threads (two is the current limit) on the same processor at once: the threads share the various on-chip execution units.  HT is available on the i7 line of processors but I just can’t justify the cost of this additional functionality.

Motherboard (Mobo)

I need to match the CPU to a -K Series motherboard and I picked the Intel Desktop Board DZ77GA-70K with Intel Z77 Express Chipset family which includes Intel High Definition Audio
Intel Desktop Board DZ77GA-70K. The Intel high-definition audio chip allows you to use your computer to send digital audio signals to speakers, headphones, telephones and other audio equipment. Early computer audio systems could only produce simple stereo sound reproduction. The Intel HD audio system supports surround sound up to Dolby 7.1.  It supports the  usual 32GB of RAM, Smart Response TechnologySmart Connect Technology, Intel Rapid Storage Technology (Intel RST) for RAID 0, 1, 5, and 10. The “GA” in the motherboard’s name means that it contains Bluetooth/WiFi and the a front panel USB 3.0 module  (“GAL” means it has no Bluetooth/WiFi). The board supports Intel’s Fast Boot Technology which can dramatically reduce the time to boot the system. Support for high end graphics boards. It has eight  USB 3.0 ports (4 external/4 header), ten USB 2.0 ports (4 external (2 Hi-Current/Fast Charging) / 6 internal), four Serial ATA 6.0 Gb/s ports, one eSATA 6.0 Gb/s, four Serial ATA 3.0 Gb/s ports and many other features.

The Mobo comes with the Intel Visual BIOS graphical interface and animated controls, which allow you to configure settings faster and take full advantage of your Intel -K processors. The Visual BIOS uses the Unified Extensible Firmware Interface (UEFI) which defines a software interface between an operating system and Mobo firmware. UEFI is meant to replace the Basic Input/Output System (BIOS) firmware interface, present in all IBM PC-compatible personal computers.

The form factor for this Mobo is ATX.  ATX (Advanced Technology eXtended) is a motherboard form factor specification developed by Intel in 1995 to improve on previous de facto standards like the AT form factor.  There are different form factor of motherboards including microATX, Standard ATX and XL-ATX.  This is important to keep in mind when picking a case.

The selling feature for me was that its an Intel product (motherboards are new to me and I need the emotional support), seems easy to setup, it has gotten reasonable reviews (and here is another), and reasonable price.  It isn’t most feature full Mobo nor what a die-hard overclocker would buy but it seems a solid, stable product that will not give me any troubles or support problems and will perform well.

Memory (RAM)

According to the September 2011 Steam hardware survey, 4GB of RAM is currently the most popular configuration among gaming PCs. This may be sufficient for a light home user, however, many power users and enthusiasts find 4GB to be insufficient. Many recommend at least 6GB for any enthusiast PC, especially in light of the relatively
Corsair Vengeance low cost of memory.  I’m going with 8GB of RAM in an effort to assure good I/O and 12GB or 16GB just seems like more than I will need.  That amount of memory seems sufficient for you average gamer and should work for me.  And the reviews I have seen also claim they have successively overclocked this memory.

I also want to keep open the option to do some overclocking, so I need to consider memory based on Intel’s  Extreme Memory Profile (XMP).  I also want a memory provider with a solid reparation.  The Intel Core i5-3570K processor requires DDR3-1333/1600 memory.  With all this in mind, I choose the 8GB (2X4 GB) Corsair Vengeance Blue, 9-9-9-24, 1.5V  PC3-12800 1600MHz DDR3 240-Pin SDRAM Dual Channel Memory.   They are not top of the line memory but seem a good fit for my needs and have gotten solid reviews.

DDR3 or DDR3 SDRAM, an abbreviation for double data rate type three synchronous dynamic random access memory, is a modern kind of dynamic random access memory (DRAM) with a high bandwidth interface, and has been in use since 2007.  The primary benefit of DDR3  over its immediate predecessor (i.e. DDR2), is its ability to transfer data at twice the rate (eight times the speed of its internal memory arrays), enabling higher bandwidth or peak data rates. The next generation,  DDR4 expected to be released to the market sometime in 2013.  Its primary benefits compared to DDR3 is the higher range of clock frequencies (200MHz vs 166MHz) and data transfer rates (400MT/s vs 333MT/s).

DDR3 memory is classified according to the maximum speed at which it can work, as well as their timings. Timing are numbers such as 3-4-4-8, 5-5-5-15, 7-7-7-21, 9-9-9-24 where lower is better. Memory speed is specified via a number like this: DDR3-xxx / PC3-yyy or DDR3-xxx/yyy. The xxx number indicates the maximum clock speed that the memory chip supports. Therefore, DDR3-1333 can work up to 1,333MHz. Note this isn’t the real clock speed but twice that speed. So the real clock speed of DDR3-1333 is 666MHz. The yyy indicates the maximum transfer rate that the memory can reach. So memory labeled as DDR3-1333/10664 has a transfer rate of 10,664MB/s or 21,328 MB/s if they are running under dual channel mode. Most current boards have dual with the Intel socket 1336 has triple channel.

The memory timings x-x-x-x indicates the number of clock cycles that it takes for the memory to perform something. The smaller the number, the faster the memory. These set of four numerical parameters are called CL, tRCD, tRP, and tRAS. Sometimes there a fifth value which is voltage. Check out Understanding RAM Timings for more information.

Memory is sold in “kits” which are simply multiple single, similar (identical as possible) RAM modules packaged together. The intention is for them to be used in motherboards that have dual and triple (etc.) RAM channel capabilities.

Graphics Processing Unit (GPU)

I’m going to try and live with the on-board graphics processing unit (GPU) integrated with the CPU and invest that money elsewhere.   The reviews of  Intel’s newest integrated GPU that comes with the i5-3570K (HD Graphics 4000 or HD 4000) have been favorable (also see this).   This is the  third and latest generation of HD Graphics (now with 16 execution units) and appears to be a real contender to low end graphics cards.  If it proves less than acceptable, I’m invest in a graphics board another day.

Sound Card

Here again, I’m not buying a separate card but using the Intel High Definition Audio integrated into the motherboard.  Frankly, I’m not sure if this will limit my GNU Radio & digital signal processing objectives but I’ll take the risk.  If I’m unhappy for any reason, I’ll buy myself a sound board.

Solid State Drive (SSD)Samsung-SSD-840-Pro

I have chosen the Samsung Electronics 840 Pro Series 2.5-Inch 128GB SATA 6GB/s for my Solid State Drive (SSD).  Samsung has a great repatriation in this space and it has gotten solid reviews.

What most people who use SSDs do (and what I plan to do) is to buy one large enough to hold the OS and applications, and also buy a hard drive to hold the rest of your documents, photos, videos, etc. That’s a good compromise which puts the most performance-critical files on the fastest drive and has the cheapest cost-per-byte for your voluminous data files which typically have much lower performance requirements.  But keep in mind that as soon as the amount of data written reaches the stated capacity of the device, the write bandwidth immediately drops.  In fact, write bandwidth reduced by up to 70-80% once fully loaded with data and continued to operate under those conditions.  Therefore, don’t fill the SSD drive.

Also, one of the most publicized downsides of SSDs is that they have a limited number of writes before they wear out—however, with most newer SSDs, this isn’t actually a problem. Most modern SSDs will become outdated before they die, and you’ll probably have upgraded by then, so there’s not really a huge need to worry about writing to the drive too many times.

Because of the high speed of the SSD, your going to want to use the 6GB/s SATA ports on the motherboard.  The standard 3GB/s SATA ports don’t have the throughput, never the less, studies show the SSD still give you benefits.

Power Supply Unit (PSU)Corsair 650W PSU

I choose the popular  Corsair TX650 650-Watt Power Supply as my PSU. Most computers only consume around 150W, and even a high end computer might consume maybe 200W. That’s why most OEM computer manufacturers put small 250-350W PSUs in their systems. If you look at online reviews of highly overclocked systems with multiple video cards (SLI/Crossfire) they consume at most about 500-600W.   I don’t believe I’ll ever approach these levels so this PSU will give me much head room.  The review I have read seem to claim that he best way to take advantage of the TX650W’s quiet qualities is  to ensure that the PSU intake air does not exceed 30°C often, nor demand more than ~350W DC output.  I believe my usage will fit in this sweat spot.

Networking

Networking capabilities are built into the motherboard.  The Mobo comes with two Gigabit (10/100/1000 Mb/s) LAN subsystems using the Intel 82579V Gigabit Ethernet Controller. It also has a Bluetooth 2.1 & WiFi 802.11b/g/n module. There appears to have been some troubles with WiFi and Bluetooth module for DZ77GA-70K in 2012, but it has been reported to Intel and hopefully this has been worked out by now.  I’ll have to make sure I update the firmware on the board when I get it.

CD-ROM / DVD Drive / Hard Drives

I’m not going to worry about this now.  I anticipate loading all my software / data from the Web or transferring from my existing hard drives.  Also, I’ll reuse my existing hard drives in this box.

Cooler

The Intel Core i5-3570K comes with a stock cooler.  If do over clock the CPU, I’m likely to need a better cooler, but this is fine for now.

CaseCooler Master HAF 912 - Mid Tower Computer Case

Picking a case has been the hardest thing for me to select.  I guess this is because its not as much a technical decision but an aesthetic choice.  I have narrowed my choose to the Cooler Master HAF 912 – Mid Tower Computer Case with High Airflow Design (19.5 x 9.1 x 18.9 inches ; 17.8 pounds).  It has gotten good reviews with the main complaint being that it needs more fans (much room for more installation but only two are provided).  The front panel comes with the older USB 2.0 ports but the Mobo comes with a USB 3.0 panel that could be install if desired.  The case isn’t expensive but still has a sharp look and seems very versatile in its use and cooling.

Monitor

The Dell LCD monitor I presently have dates back to 2006 and isn’t equipped with HDMI, which is the only way to interface with the Mobo.  I presently use my monitor via its Digital Video Interface Digital (DVI-D), but it also has Video Graphics Array (VGA) and Composite Video inputs.  So if I wish to continue to use the monitor, I’ll need a converter of some type.  I found that the DVI-D to HDMI can be done via an inexpensive cable, so that is the way I’m going.  I specifically need a HDMI Type A to DVI-D Dual Link Male to Male cable.

Operating System (OS)

I plan to install Ubuntu Linux on the SSD drive.  Picking the Linux distribution was nearly as hard as picking the case.  I choose Ubuntu because of its popularity and I wanted to experience its desktop environment once again, GNOME.  I used GNOME many years ago when it was very young, I saw potential, and I would like to see how it has grown. I plan to spend the vast majority of my time within Xterm at the command prompt, but I also want to get familiar with Ubuntu/GNOME.  I’ll also do most of my systems administration at the command prompt, but again, getting familiarity with Ubuntu would be good to know.

How do I plan to installing Ubuntu, given that I will not have a OS already installed and I will not have a CD-ROM/DVD?  Ubuntu does have an ability to be installed via an USB stick.

I’m not going to abandon MS Windows.  I have many tools that I use in Windows and its not practical to just abandon them for something else, at least not right now.  I would like to dual boot the system with Linux and MS Windows.  Ideally, I’ll keep my old Windows image on my current PC’s hard drive, put that drive in my new system, and have the hard drive be my second OS on the bootloader’s chain of operating systems.  I know this could be done if I choose to re-install MS Windows and all my applications but I don’t know the challenges I’ll face given I’m using an establish image …. it will be a learning opportunity!

If I’m forces to do a re-install of MS Windows, I might us Oracle VM VirtualBox, which is a x86 virtualization software package. VirtualBox can be installed on an existing host operating system as an application; this host application allows additional guest operating systems, each known as a Guest OS, to be loaded and run, each with its own virtual environment.  The typical way of installing a guest operating system is to install it from the ground up. In general, you don’t see VirtualBox running a guest operating system from an existing drive or partition.  Never the less, a search of the Web does show evidence that people have made it work this way (1, 2, 3, 4, 5, 6, 7).

The last, and least desirable approach (for my needs) is to use Windows applications is via Wine.  Wine (originally an acronym for “Wine Is Not an Emulator”) is a compatibility layer capable of running Windows applications on Linux. Instead of simulating internal Windows logic like a virtual machine or emulator, Wine translates Windows API calls into Linux calls on-the-fly, eliminating the performance and memory penalties of other methods and allowing you to cleanly integrate Windows applications into your desktop.  Since it doesn’t create a virtual machine programs perform faster than in a VM.  However, you’ll need to test it with your application since it doesn’t support all programs.  Also, you’re not running MS Windows, just the MS Windows compatible applications.  This is fine if your interest in running Excel standalone, but you can’t perform anything that requires the MS operating system.

Boot Loader

A boot loader is the first software program that runs when a computer starts. It is responsible for loading and transferring control to the operating system kernel software. The kernel, in turn, initializes the rest of the operating system.  GRUB (GRand Unified Bootloader) is a boot loader package developed to support multiple operating systems and allow the user to select among them during boot-up.  GRUB is often the default boot loader for Linux and is preferred to MS Windows since it makes up for numerous deficiencies while providing full-featured command line and graphical interfaces.  GRUB is the default boot loader for Ubuntu, making it an easy choose.  GRUB is powerful and complex so check out How I configured grub as the default bootloader on a UEFI Boot systems.

What does it Cost

Now that I have a plan, what will all this cost?  I estimate it will be $765, less than one-third the cost of my present system.  Granted I’ll be reusing the monitor, key board, mouse, and some drives but this is a substantial price difference for what will be a much more capable machine.

cost

To see what I finally implemented, check out Building My Linux Box…The Implementation.

Conky for the Raspberry Pi

Conky  is a Linux system monitor tool using X Windows.  Conky is highly configurable and is able to monitor many system variables including the status of the CPU, memory, swap space, disk storage, temperatures, processes, network interfaces, battery power, system messages, e-mail in-boxes  Linux updates, runs many popular music players, and much more. Unlike system monitors that use high-level widget tool-kits to render their information, Conky is drawn directly in an X window, allowing it to consume relatively fewer system resources.

To install the standard Conky package, use the following:

sudo apt-get install conky-std

Two sites you will want to read, beyond the Conky manual page are the lists of Config Settings and Variables. You use the Config Settings to describe general features of how you want your Conky to appear, and the variables to define what actually gets displayed.

The color names that are used within Conky are the X11 colors located in /usr/share/X11/rgb.txt.  There isn’t a standard set of colors to be found on any X Window system, so you’ll need to inspect this file to get some idea of what color names you can use.  This X color name list, which appears to be larger than what is in the RPi’s rgb.txt file, could help you visualized the colors.

Conky uses a configuration file location in $HOME/.conkyrc.  Conky can be configured in an amazing number of way but I’m using the following configuration on the RPi:


# --------------------------------------------------------------------------------------------- #
#
# .conkyrc - derived from various examples across the 'net
#
# Some of the sites that proved most usful include:
#   http://mylinuxramblings.wordpress.com/2010/03/23/how-to-configure-the-conky-system-monitor/`
#   http://crunchbanglinux.org/wiki/conky
#   http://lusule.wordpress.com/2008/08/07/how-to-4/
#
# --------------------------------------------------------------------------------------------- #

# -------------------- Conky's Run Time Parameters -------------------- #

update_interval 2.0                     # Conky update interval in seconds
total_run_times 0                       # Number of updates before quitting.  Set to zero to run forever.
no_buffers yes                          # Subtract file system buffers from used memory?
cpu_avg_samples 2                       # Number of cpu samples to average. Set to 1 to disable averaging
net_avg_samples 2                       # Number of net samples to average. Set to 1 to disable averaging

# -------------------- Conky's General Look & Feel -------------------- #

# --- defualt values --- #
default_color grey                      # Default color and border color
default_bar_size 0 6            # Specify a default width and height for bars.
default_gauge_size 25 25        # Specify a default width and height for gauges.
default_graph_size 0 25         # Specify a default width and height for graphs.
default_outline_color green     # Default border and text outline color
default_shade_color yellow      # Default border and text shading color

# --- predefined colors - http://www.kgym.jp/freesoft/xrgb.html --- #
color0 FFFFFF                           # white
color1 FFA500                           # orange
color2 B22222                           # firebrick
color3 696969                           # dim gray
color4 D3D3D3                           # light gray
color5 2F4F4F                           # dark slate gray
color6 FFEC8B                           # light golden rod
color7 54FF9F                           # sea green
color8 FF8C69                           # salmon
color9 FFE7BA                           # wheat

# --- window layout & options --- #
own_window yes                          # Conky creates its own window instead of using desktop
own_window_type normal          # If own_window is yes, use type normal, desktop, or override
own_window_transparent yes      # Use pseudo transparency with own_window?
own_window_colour blue          # If own_window_transparent is no, set the background colour
double_buffer yes                       # Use double buffering (reduces flicker)
use_spacer right                        # Adds spaces to stop object from moving
maximum_width 600                       # Maximum width of window in pixels
own_window_hints undecorated,below,sticky,skip_taskbar,skip_pager

# --- window placment --- #
alignment top_right

# --- borders, margins, and outlines --- #
draw_graph_borders yes          # Do you want to draw borders around graphs
border_inner_margin 9           # Window's inner border margin (in pixels)
border_outer_margin 5           # Window's outer border margin (in pixels)
gap_x 10                                        # Gap between borders of screen and text (on x-axis)
gap_y 40                                        # Gap between borders of screen and text (on y-axis)
border_width 10                         # Window's border width (in pixels)

# --- Text --- #
draw_outline no                         # Do you want ot draw outlines
draw_shades no                          # Do you want to draw shades
draw_borders no                         # Do you want to draw borders around text
uppercase no                            # set to yes if you want all text to be in uppercase
use_xft yes                                     # use the X FreeType interface library (anti-aliased font)
xftfont Monospace:size=8:weight=bold    # Xft font to be used

# -------------------- Conky's Displayed System Monitoring Parameters -------------------- #
TEXT
# Title / Banner message
${color5}
${alignc 40}${font Arial Black:size=22}${time %H:%M:%S}${font}
${alignc}${time %A} ${time %B} ${time %d}, ${time %Y}
$color

# General system information
${color1}SYSTEM INFORMATION ${hr 2}$color
${color0}System: $color$nodename ${alignr}${color0}Uptime: $color$uptime
${color0}Kernel: $color$kernel${alignr}${color0}Arch: $color$machine
${color0}Frequency: $color$freq MHz
${color0}Serial No.: $color${execi 99999 grep Serial /proc/cpuinfo | awk '{ print $3 }'}
${color0}MAC Address: $color${execi 99999 cat /sys/class/net/eth0/address }

# CPU information
${color1}CPU ${hr 2}$color
${color0}Avg. Load: $color $loadavg
${color0}CPU Temperature: $color${acpitemp}°C
${color0}CPU Usage:$color $cpu% ${color7}${cpubar}
${cpugraph 0000ff 00ff00}$color

# Top running processes
${color1}TOP 5 PROCESSES ${hr 2}$color
${color0}Processes:$color $processes  ${color0}Running:$color $running_processes
${stippled_hr 2}
${color0}CPU Usage$color
${color3} NAME              PID    CPU %   MEM$color
${color2} ${top name 1} ${top pid 1} ${top cpu 1} ${top mem 1}$color
 ${top name 2} ${top pid 2} ${top cpu 2} ${top mem 2}
 ${top name 3} ${top pid 3} ${top cpu 3} ${top mem 3}
 ${top name 4} ${top pid 4} ${top cpu 4} ${top mem 4}
 ${top name 5} ${top pid 5} ${top cpu 5} ${top mem 5}
${stippled_hr 2}
${color0}Mem Usage$color
${color3} NAME              PID    CPU %   MEM$color
${color2} ${top_mem name 1} ${top_mem pid 1} ${top_mem cpu 1} ${top_mem mem 1}$color
 ${top_mem name 2} ${top_mem pid 2} ${top_mem cpu 2} ${top_mem mem 2}
 ${top_mem name 3} ${top_mem pid 3} ${top_mem cpu 3} ${top_mem mem 3}
 ${top_mem name 4} ${top_mem pid 4} ${top_mem cpu 4} ${top_mem mem 4}
 ${top_mem name 5} ${top_mem pid 5} ${top_mem cpu 5} ${top_mem mem 5}

# Memory and swap space untilization
${color1}MEMORY & SWAP ${hr 2}$color
${color0}RAM Usage: ${color}$mem / $memmax
$memperc% ${color6}${membar}$color
${stippled_hr 2}
${color0}Swap Usage: ${color}$swap / $swapmax
$swapperc% ${color6}${swapbar}$color

# File System utilization
${color1}FILE SYSTEM ${hr 2}$color
${color0}SD Card:$color ${fs_used /} / ${fs_size /}
${fs_used_perc /}% ${color8}${fs_bar /}$color
${stippled_hr 2}
${color0}Reads: $color$diskio_read/s${alignr}${color0}Writes: $color$diskio_write/s
${color8}${diskiograph_read 20,100 33FF00 FF3333 scale -t}$color${alignr}${color8}${diskiograph_write 20,100 33FF00 FF3333 scale -t}$color

# Ethernet utilization
${color1}NETWORKING ${hr 2}$color
${color0}Wired (${addr eth0})
${color0}Down:$color ${downspeed eth0}/s ${alignr}${color0}Up:$color ${upspeed eth0}/s
${color0}Total:$color ${totaldown eth0} ${alignr}${color0}Total: $color${totalup eth0}
${color0}${downspeedgraph eth0 25,120 000000 00ff00} ${alignr}${upspeedgraph eth0 25,120 000000 ff0000}$color
${stippled_hr 2}
${color0}Wireless (${addr wlan0})
${color0}Down:$color ${downspeed wlan0}/s ${alignr}${color0}Up:$color ${upspeed wlan0}/s
${color0}Total:$color ${totaldown wlan0} ${alignr}${color0}Total: $color${totalup wlan0}
${color0}${downspeedgraph wlan0 25,120 000000 00ff00} ${alignr}${upspeedgraph wlan0 25,120 000000 ff0000}$color

# Print the tail of the Linux message log
${color1}LOG FILES ${hr 2}$color
${color0}Linux Message Log$color
${color4}${font Arial:size=6}${execi 30 tail -n3 /var/log/messages | fold -w50}$color$font

Debugging Conky

An easy way to force Conky to reload your ~/.conkyrc configuration file is to us the command killall -SIGUSR1 conky. This saves you the trouble of having to kill and then restart.  I also discovered that  while conky is running and your concurrently editing the .conkyrc file in vi, saving the file appears to cause conky to restart and read the new .conkyrc … nice.

Installing Packages into the Raspberry Pi’s Linux

Once I got the RPi up and running headless on my local network, its time to build the software foundation that I’ll need to make it an effective development environment.  These are the packages that I loaded to get myself up and running.

Do Your House Cleaning First

I’m loading software via the Linux apt-get utility and you need to make sure its database is up to date. First thing to do is to update apt-get’s local database with server’s pkglist’s files.  Then checks for outdated packages in the system and automatically upgrades them.  Execute the following commands:

sudo apt-get update
sudo apt-get upgrade

Search for Package or Package Description

Some times you don’t know package name but aware of some keywords to search the package.  To search for packages, use the following:

apt-cache search "text-to-search"
apt-cache search "text-to-search" | grep "more-search-text"

Synaptic

Synaptic is a graphical package management program for Linux software. It provides the same features as the apt-get command line utility with a X Windows GUI front-end.  While I will not be using X Windows at this moment, in the future I will and synaptic is a very nice alternative to apt-get when in in X Windows.

sudo apt-get install synaptic

Vim

Vim is a highly configurable text editor and widely available for many different platforms.  Emacs also has a large following, but I think everyone needs to be prepared to use vim if your serious about Linux.  The RPi Linux distribution appears to have vi loaded but vim is a superior tool.

sudo apt-get install vim
sudo apt-get install vim-gtk

PyRoom

PyRoom is a a fullscreen editor without buttons, widgets, formatting options, menus and with only the minimum of required dialog windows, it doesn’t have any distractions and lets you focus on writing and only writing.  It is the polar opposite of Vim, and as such, is a good editor for the novice or casual user, but requires X Windows and Python.

sudo apt-get install pyroom

Git

Given that I plan to hack some to-be-determined applications using the RPi, I should consider establish some tools for  source code management. The last time I did serious software development in Linux (really Unix), I was using Source Code Control System (SCCS). The tools are much improved now and git is hands down the way to go.

sudo apt-get install git

Chromium

We all have a favorite browser and I choose chromium for my RPi.  Chromium serves as a base for Google Chrome, which is Chromium re-branded (name and logo) with very few additions.

sudo apt-get install chromium

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