Centos: Update Drupal via Drush

Updating your drupal instance with Drush is a fast and easy way to get the things done:

1. check if pear is installed

# pear version
PEAR Version: 1.9.4
PHP Version: 5.3.3
Zend Engine Version: 2.3.0

2. add the drush channel

# pear channel-discover pear.drush.org
Adding Channel "pear.drush.org" succeeded
Discovery of channel "pear.drush.org" succeeded


3. change to the folder where your drupal site is installed

example given:

# cd /public_html/site_xy

4. update to the new drupal version (example drupal 7.24)

# drush pm-update projects drupal-7.24


you are done

Further documentation on drush specific installation issues:
https://drupal.org/node/1791676

How to remove a Raid Interface

If you are unsure about your raid volumes:

# mdadm --detail /dev/md1

or to get your different md's

# cat /proc/mdstat
 

To remove an existing RAID device, first deactivate it by running the following command as root:

# mdadm --stop raid_device  

Once deactivated, remove the RAID device itself: 

# mdadm --remove raid_device

Finally, zero superblocks on all devices that were associated with the particular array: 

# mdadm --zero-superblock component_device…

Example Removing a RAID device

Assume the system has an active RAID device, /dev/md3, with the following layout:

# mdadm --detail /dev/md3 | tail -n 4
    Number   Major   Minor   RaidDevice State
       0       8        1        0      active sync   /dev/sda1
       1       8       17        1      active sync   /dev/sdb1
       2       8       33        2      active sync   /dev/sdc1

In order to remove this device, first stop it by typing the following at a shell prompt:

# mdadm --stop /dev/md3
mdadm: stopped /dev/md3

Once stopped, you can remove the /dev/md3 device by running the following command:

# mdadm --remove /dev/md3

Finally, to remove the superblocks from all associated devices, type: 

# mdadm --zero-superblock /dev/sda1 /dev/sdb1 /dev/sdc1