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A list of Frequently asked questions and answers to them.
Godzirra user name: bob pw: ginger root pw: bob
~Michael Short
~Michael Short
~Michael Short
~Michael Short
-Kenneth Denson
— Matthew Taft 2010/05/17 18:18
— Matthew Taft 2010/05/17 18:18
==What is so special about using this?==
— Matthew Taft 2010/05/20 22:19
==How easy is this to implement?==
— Matthew Taft 2010/05/20 22:19
==Is there an option that allows for a little less of a high end machine to be used as the server?==
— Matthew Taft 2010/05/20 22:19
-Kenneth Denson
aptitude install mdadm
-Kenneth Denson
To mount:
mount
mount /dev/md0 /mnt
-Kenneth Denson
To unmount:
~Michael Short
To zero out drives:
~Michael Short
Another command for zeroing out the drives:
— Bradley Hammond 2010/05/19 10:50
cat /proc/mdstat
-Kenneth Denson
— Matthew Taft 2010/05/17 18:31
~Michael Short
~Michael Short
— Bradley Hammond 2010/05/18 12:13
— Bradley Hammond 2010/05/18 12:13
— Bradley Hammond 2010/05/18 12:39
— Bradley Hammond 2010/05/19 10:57
— Bradley Hammond 2010/05/20 12:49
xm -list
will list the current running VMs.-Kenneth Denson
shutdown -h now
will shutdown whatever severs terminal you enter it into.
-Kenneth Denson
Q: If you try to shutdown a Virtual Machine normally and it will not shutdown what command can you use to stop it?== [jbrant]
A: xm destroy domain-name [jbrant]
Q: What command can you use to move a virual machine from one vm server to another vm server with out shutting it down? [jbrant]
A: xm migration [jbrant]
Q: Can you have virtual machines using different operating system on the same vm server? [jbrant]
A: No because each guest is copy of the original Kernal. [jbrant]
Q: How would you make a virtual disk? [jbrant]
A:
dd if=/dev/zero of=/xen/domains/vm14/vicepa.disk count=900 bs=1M ^ ^ ^--------------------------+ Name of virtual disk Number of blockes |-Size of blockes [jbrant]
Q: Can you build a server cluster across multiple subnets? == [jbrant]
-Kenneth Denson
what do you need to create a 12 monitor video wall * definately 12 monitors and 6 machines will be needed along with a switch and a long mudkip video * Jeff jansen just rules
Q: How do you update source.list? == [jbrant] A: aptitude update <enter>
aptitude upgrade <enter> [jbrant]
Q: How can you check to see what packages have been installed? == [jbrant]
A: dpkg -l will list installed packages [jbrant]
Q: What is the 'make' command used for? [jbrant]
A: To determine automatically which pieces of a large program need to be recompiled, and issue the command to recompile them.
Q: How do you uninstall an application or driver? [jbrant]
A: aptitude purge application [jbrant]
Q: What is the difference between aptitude and apt-get == [jbrant]
A: One difference is that aptitude keeps logs. The log file is located at /var/log/aptitude [jbrant]
Q: What if aptitude can't install the package I want?
A: Almost every package can also be installed from source from the site. To do this download the source archive, extract it and follow the instructions usually enclosed within. Usually this involves running a script called configure within the folder the archive extracts to. Then running make and make install. Any changes to this will normally be listed in the instructions.
— Matthew Taft 2010/05/17 20:41
Q: How do I search for packages using aptitude?
A: aptitude search *Possible package name*
— Bradley Hammond 2010/05/18 13:36
Q: Aptitude is installing more than I want it to, is this okay?
A: This is most likely because the package you told it to install needed some extra things that were found in those other packages, it's normal.
— Matthew Taft 2010/05/20 22:17
== What are the versions of Debian name after? == [jbrant]
== How do you mount a peripheral device? == [jbrant]
echo $(($RANDOM%10+1))
— Bradley Hammond 2010/05/20 12:56
<nowiki>COMMAND_LINE</nowiki>
— Bradley Hammond 2010/05/20 13:14
echo ${array[$sub]}
But if you want to see everything lumped together use the following:
echo -n ${array[$sub]}
— Bradley Hammond 2010/05/20 13:25
Q: How do I transfer files fromlab46 account to my home Linux system?
A: Put Files that need to be transferred into Public_html
wget http://lab46.corning-cc.edu/~$USER/filename .
Q: How do i transfer files from my home system to my lab46 account?
A: got to the directory were your file is located
scp filename $USER@lab46.corning-cc.edu:~/
Q: What file permissions are needed to use wget?
A: (a+r) -rw-r–r–
Q: What file permissions are needed to view a webpage?
A: (a+r) -rw-r–r–
Q: What file permissions are needed for a web page to access the contents of a folder?
A: (a+x) drwx—–x
Q: How do i get the raw data from my wiki jornal into lab46?
A:
wget http://www/journal/spring2010/$USER/week1
Q: How do i look at log files that only pertain to me?
A: using swatch documentation:swatch
Q: how do i add a style sheet to a lab46 public_html web page?
A: place your stle.css file in the public_html directory and within the head section of your web page add
<style type+"text/css"> @import "style.css" </style>
welcome to the section ginger the hottest club in all of asia.
so how do you remove directories you ask?
you simply do the command : rmdir (directory name here)
and jesse short your use of the ginger racist slurr is unnecessary i will find you in your sleep and kill you
how do i crate raid with he os on one of the hard drives?
you will need to set up the raid when you are installing the os such as ubuntu.
What shoud i do if i cannot get my computer to connect to the network?
one of the first steps would be to check the ethernet cable to see if it is connected at both ends.
how do i access the irc network?
well you start by opening a screen session then type irssi /server irc then join the channels you want to
Q: What is MPI?
A: MPI stands for Message Passing Interface. It is a widely used protocol for passing information to be processed on a cluster of computers.
Open MPI can be found here: http://linux.softpedia.com/get/System/Clustering-and-Distributed-Networks/Open-MPI-7359.shtml
Q: What is cluster computing?
A: A computer cluster is a group of two or more homogeneous computers networked and configured to provide access to parallel processing.
Q: What is parallel processing?
A: Parallel processing breaks up the data to be processed and sends the individual sections to a computer or processor to be independently calculated or modified. The sections are then returned to the calling computer and re-assembled via MPI. This has the net effect of shortening the processing time as the work is distributed over the cluster.
Q: What is scp??
A: SCP stands for secure copy, its a quick and easy way to transfer files between computers and hosts. This can be performed as shown:
$ scp filename bob@bob.com:~/filebackup
This will copy a file from your current folder named “filename” and place it in the backup folder under the home directory at bob.com.
Q: What is cURL and how is it useful?
A: cURL (Cambridge University Robot Language) is/was intended to be an easy to use replacement for html/javascript. A useful attribute of cURL is that it can simulate user interaction to a web page, providing means of logging in and modifying existing sites and user information.
Q: What is chromium and where can I find it?
A: Chromium allows parallel graphical rendering across a cluster, supporting openGL it allows fast graphical rendering and advanced graphics.
Chromium can be found here: http://chromium.sourceforge.net/
Q: What are some examples of distributed processing?
A: There are quite a few programs out there that use the idle time of home PC's to perform complex calculations. The net result is a massive amount of calculations that would otherwise be impossible. A prime example is the Seti@home project. There are currently over 5.2 million users that have returned over two million years of accumulated computing time, and over 10^21 floating point operations, unfortunately, ET has not phoned home yet…
Q: Ok, how do you time how fast it takes a program to run?
A: Just type the word “time” before executing the program, simple eh? Like this:
$ time ./thisprog
You will have time statistics returned when execution is over. This is useful when optimizing a program, or comparing single run to cluster run times.
Q: What is a KVM?
A: A KVM stands for keyboard, video, mouse. It is an adapter that allows you to connect multiple computers and select which you control via one keyboard, monitor, and mouse.