January 2015
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January 2015
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12131415161718
19202122232425
262728293031  

How To create a local mirror of latest Red Hat Enterprise Linux without using Satellite server

How To create your own local Red Hat Enterprise Linux yum repository server

To begin, build a virutal machine or stand alone system installing the same OS version of Red Hat you wish to serve as the yum repository. At the time of this writing, my base OS plus mirror data consumed 14G of disk […]

How to find dead links and delete them

Sometimes, after performing VPS migrations, the soft links in /etc/vz/conf may not be removed. Over time, the dead links may build up and cause many ‘No such file or directory’ messages when trying to look for common settings amonst all conf files (ie cat /etc/vz/conf/*.conf | grep whatever). Quick easy way to delete these dead […]

udev assigns incorrect number to eth device

eth interface number changes and is not what is expected

During a recent exercise where I created a RedHat 6.3 virtual machine, clones of that virtual machine each had different numbers assigned to their respective eth device(s). I’ve run into this booger before in the past and remembered that udev creates a persistent rule in […]

passwd: Authentication token manipulation error

Check if /etc/shadow exists. If it doesn’t, run the command ‘pwconv’ then try changing the user password again.

How to check if Large File Size (LFS) is enabled

To check if a file system supports the LFS standard, you can use the getconf command. If the result is 64, LFS is supported. getconf FILESIZEBITS /

In the example above, the root file system was checked. If /var for example, is a separate file system, specify /var in its place. You may also use […]

How to disable cron based mail alerts

How to disable cron based mail alerts The easiest way to disable cron based email alerts is to append the following to the specified command within the users crontab:

>/dev/null 2>&1

Example:

# m h dom mon dow command 59 23 * * * /root/scripts/hotfixes/vzagentdb.sh >/dev/null 2>&1 CRONDARGS=’-m off’ in /etc/sysconfig/crond may also be specified […]

Create a temp file with random characters

tmpfile=`/bin/mktemp /var/log/rpmpkgs.XXXXXXXXX` || exit 1

System hangs during messagebus startup

System hangs during messagebus startup This problem has been experienced after rebooting a system in which ldap has been configured. Note that LDAP functions properly immeidately after it is setup on the machine, but hangs at “staring system message bus” after a reboot. To fix, reboot in single user mode or into linux rescue and […]

Resizing an Online Multipath Device

Resizing an Online Multipath Device

If you need to resize an online multipath device, use the following procedure:

1. Resize your physical device

2. Use the following command to find the paths to the LUN:

# multipath -l 3. Resize your paths. FOr SCSI devices, writing a 1 to the rescan file for the device […]

How to share ssh command line with someone via screen

Use screen to share an ssh session It’s quite easy to share an ssh session with someone remote so that they can view the ssh session. This process works well if everyone involved has root access. Read further below if this is not the case. To begin, screen must be installed to create the screen. […]