CentOS / Redhat: Chroot And Mount Raid Or Actual Hard Disk From Rescue Kernel / CD

Posted on in Categories last updated June 24, 2010

Something is wrong with my RHEL networking configuration so I booted using my ISPs remote rescue kernel mode to fix my system. How do I mount and chroot into actual installation to fix the problem? How do I boot from any Live Linux CD and chroot into /dev/sda1 or /dev/md0 to fix the problem or recover the data?

Howto rebuilding a RAID array after a disk fails

Posted on in Categories , , last updated December 27, 2007

Q. I have two disk-mirrored array, suppose if one of my disk in mirrored RAID array fails, then I will replace that disk with new one (I have hot swapping SCSI drives). Now question is how I rebuild a RAID array after a disk fails.

A. A redundant array of inexpensive disks, (redundant array of independent disks) is a system, which uses multiple hard drives to share or replicate data among the drives. You can use both IDE and SCSI disk for mirroring.

If you are not using hot swapping drives then you need to shutdown server. Once hard disk has been replaced to system, you need to use used raidhotadd to add disks from RAID-1, -4 and -5 arrays, while they are active.

Assuming that new SCSI disk is /dev/sdb, type the following command:# raidhotadd /dev/mdX /dev/sdbReplace /dev/mdX with actual raid device name (e.g. /dev/md0). While array is under construction, you can see progress and other information by typing following command:# cat /proc/mdstat

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