Tags
centos, centos 6, command line, document viewing, evince, pdf, terminal
assuming the pdf is called foo.pdf
type:
evince foo.pdf
29 Monday Apr 2013
Posted Uncategorized
inTags
centos, centos 6, command line, document viewing, evince, pdf, terminal
assuming the pdf is called foo.pdf
type:
evince foo.pdf
29 Monday Apr 2013
Posted Uncategorized
inthis one is by far the easiest install on centos 6 I have seen to date.
Su
yum install R
25 Thursday Apr 2013
Posted Uncategorized
inTags
What is your update cycle like? |
Do we have access to the updates? |
How do we update? |
Are you willing to provide us with emergency patches? |
What level of integration would you have with centos 5, redhat 5, redhat 6, windows 7? |
Do you offer a trial period? |
What is your company support like? |
What is your relationship to the open-source community? IRC, wikis, forums? |
Do you provide free documentation? |
What is the copyright status of your documentation? |
Could we share your documentation with a 3rd party contractor? |
Are there external resources for this software such as books? |
What products would you say this software works well with as compliments? |
Do you run on the token model? |
How long has your firm been in operation? |
Has your software been used on a high availability cluster in the past? |
What would you consider to be the ideal setup for your software OS |
What would you consider to be the ideal setup for your software softwarepackages |
What would you consider to be the ideal setup for your software hardware |
What would you consider to be the ideal setup for your software network |
What tutorials do you offer? |
What hours are support lines open? |
How much does support cost? |
Can you name a few customers that you currently have? |
What do they use your product for? |
Working with your primary customers what lessons have you learned? |
Do you have a requested feature process? |
If so, what is it? |
Do you have any white papers or any supporting material that compares your product with the competitor? |
Are output and configuration files in human-readable form? |
15 Monday Apr 2013
Posted Uncategorized
inCould god make a CAD tool so complex that even he had to read the forums in order to operate it?
I can fix anything with another cap, now if I only had the room to place it in.
The metric units for noise are wrong. V/sqr(Hz) doesnt help me. It should be in units of pain it will take for me to reduce it. It will, for example, take me 10 Milli-divorces to reduce my noise 5%
You can push humans a lot harder then you can push machines, because machines dont feel pain. We should get to work on that problem.
Probability is what I use when all else fails. It is the equivalent of cannibalism after a plane crash. Except I eat my own Ego rather then those around me. Those around me have long ago managed to get away from the dying project.
I can lie to my boss, but my design always knows the truth.
10 Wednesday Apr 2013
Posted Uncategorized
inTags
Get into root
su
use yum command to install perl
yum install perl
when asked to confirm select y
y
I find it a good idea to check the yum log afterwards
tail /var/log/yum.log
you should see quite a few entries about perl, here is my sample:
Apr 10 12:59:24 Updated: 1:perl-Module-Pluggable-3.90-130.el6_4.x86_64
Apr 10 12:59:25 Updated: 1:perl-Pod-Simple-3.13-130.el6_4.x86_64
Apr 10 12:59:25 Updated: 4:perl-libs-5.10.1-130.el6_4.x86_64
Apr 10 12:59:33 Updated: 4:perl-5.10.1-130.el6_4.x86_64
Apr 10 12:59:33 Updated: 1:perl-ExtUtils-ParseXS-2.2003.0-130.el6_4.x86_64
Apr 10 12:59:35 Updated: 4:perl-devel-5.10.1-130.el6_4.x86_64
Apr 10 12:59:36 Updated: perl-Test-Harness-3.17-130.el6_4.x86_64
Apr 10 12:59:37 Updated: perl-ExtUtils-MakeMaker-6.55-130.el6_4.x86_64
Apr 10 12:59:37 Updated: perl-Test-Simple-0.92-130.el6_4.x86_64
Apr 10 12:59:38 Updated: perl-CGI-3.51-130.el6_4.x86_64
exit out of root
exit
after it is done, we want to check it
rpm –qa perl
you should receive an output along the lines of:
perl-5.10.1-130.el6_4.x86_64
10 Wednesday Apr 2013
Posted Uncategorized
inThis guide should be good for most major distros out there but I have only tested it so far in centos 6. Sadly, there is a strange error message I am getting when decrypting that I have yet to discover how to fix, if anyone knows anything about it feel free to let me know, I will update if I find a workaround:
Create a file
touch foo
open the file
nano foo
write example text, I used
I’m on an encrypted system now.
Close the file and get ready to generate your key, but first verify that you have gpg installed
which gpg
It should show it in some place like /bin, if not install it. Assuming it was there type
gpg –gen-key
it asked me what type I wanted I choose 2, which is DSA only.
2
Now it asks me the key size, I choose the maximum of 3072
3072
Now, it asks me for the duration of time the key will be valid, I choose 6 months
6m
It asks me to confirm
Y
It asks me for my real name
John Q. Public
It asks me for my email address
it asks me to comment
temp key, used for one project
it gives me several options to correct it, everything looked fine so I selected O for okay
O
It asks me for a passphrase
Very LoNg password with 55 numbERS
It will now tell me to generate entropy, I used a floating point benchmark test and a lot of random typing to do this. After it is done, I test it on my file
gpg –c foo
it will prompt me for my passphrase twice and after I enter it, I check my directory
ls
and I see my encrypted file
foo.gpg
now, I want to decrypt it
gpg –o goo –d foo.gpg
I am asked my pass phrase
And I view my file
cat goo
now, I am assuming you are just going to use this key with a few people, so first we export our public key
gpg –armor –export > /home/myname/mypublickey
if you would open this file you will see the public key, which you can send out.
REFERENCES:
http://www.centos.org/docs/4/html/rhel-sbs-en-4/s1-gnupg-import.html
10 Wednesday Apr 2013
Posted Uncategorized
inTags
This guide is based heavily on the official redhat documentation for deployment: https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Deployment_Guide/index.html
You will need root for this and type in your password
su
go to the directory with your interfaces
cd /etc/sysconfig/network-scripts
now create a new interface for the link
touch ifcfg-bond0
now we are going to alter eth0 and eth1 so we want to save them
cp ifcfg-eth0 /home/yourname/original_eth0 && cp ifcfg-eth1 /home/yourname/original_eth1
you can verify that they are present by typing
ls /home/yourname original*
now we alter eth0
nano ifcfg-eth0
add the following:
MASTER = bond0
SLAVE=yes
USERCTL=no
Do the same with ifcfg-eth1
Now, we need to load the channel bonding kernel module, to do this we go into the modprobe area
cd /etc/modprobe.d
we create a new configuration file
touch bonding.conf
we go into the file and add an alias
nano bond0 bonding
and type
alias bond0 bonding
now I restart the service
service network restart
now check the status
cat /proc/net/bonding/bond0
after this is done you should configure the settings. Which will be covered later as they require empirical customization.
04 Thursday Apr 2013
Posted Uncategorized
inTags
Today I will show you how you can monitor system resources to determine what types of activities are occurring on your cluster.
We begin with a command called: sar
This command comes standard with centos 6, check to see if you have it by typing
whereis sar
A cool feature about sar is that it doesn’t require root access to operate. So, let’s give it the first command.
sar –u
the first line will show you the kernel version, the domain name, today’s date, 64 or 32 bit, and the number of cpu. So for me:
Linux 2.6.32-358.el6.x86_64 (mydomainfortest.net) 04/04/2013 _x86_64_(4 CPU)
After this it will show logs every 10 minutes with all my restarts. Now, we can get a live view:
sar –u 1 30
this will update every second 30 times. I can change the number to get different refresh rates.
In case you want more information you can always add the ALL flag
sar –u ALL
now, one of the nice things about having sar is that it does save a log which can be found at:
/var/log/sa
The trouble is that it is not in human readable form so we must use the sar utility to read the files. The sar command has a flag –f that allows this.
sar –u –f /var/log/sa/sa04
this will display the logs on the 4th day of the month.
Now, for something pretty cool. Say I want to see a live update on one core, say core 3
sar –P 3 1 1
I can also do this for all the cores:
sar –P ALL 1
So, I can combine terms. Like one I used this morning:
sar –u –f sa04 –s 01:09:00 –e 08:10:55 –P ALL
which gives me “sar logs on the 4th day for each core of the month between 1:09:00 am to 08:10:55am”.
You can also view the memory used with the –r flag
sar -u -f sa04 -s 07:50:00 -e 15:10:55 –r
which gives me “sar logs on the 4th day on the memory of the month between 07:50:00 am to 03:10:55pm”.