Replacing a Damaged Scsi Software Raid 1 With a Larger Ide Raid 1 on E-Smith
Note: To get the best performance from raided ide drives they should be set as masters on the primary and secondary channels.
ie. hda and hdc
Step-1 - boot knoppix from CD and image good scsi drive to new ide drives
Pull up terminal as root
$ su
Image drives, where sdx is the remaining good drive either sda or sdb
# dd if=/dev/sdx of=/dev/hda
# dd if=/dev/sdx of=/dev/hdc
This step take quite some time (in the order of hours) so be patient
Step-2 - move and resize partitions to use larger hard drive space
Reboot knoppix with no swap device
# knoppix noswap
Pull up terminal as root
$ su
Use graphical interface to move swap partition to end of the drives
# qtparted
select hda
right click on the swap partition and select move
type 0 in the "Free space after" box and press tab.
click OK
click Device and select commit
repeat for hdc
Resize root partition to take up remaining free space (qtparted doesn't support ext3 so must use parted)
# parted /dev/hda
(parted) print
write down the size of the starting positions of the root (Minor 2) and swap (Minor 3) partitions and call them r & s
(parted) resize 2 r s
(parted) quit
repeat for hdc
Step-3 - edit raidtab file and copy to knoppix file system
Mount root partition of new ide drive
right click hda2 icon on desktop
click mount
right click hda2 icon again
click Actions, Change read write mode
click ok to change to write
# mcedit /mnt/hda2/etc/raidtab
Change all sda to hda and all sdb to hdc and save
Now copy the raidtab file from your real root filesystem to the current root filesystem.
# cp /mnt/hda2/etc/raidtab /etc/raidtab
Step-4 - unmount filesystems
In order to start the raid devices, and sync the drives, it is necessary to unmount all the temporary filesystems.
# umount /mnt/hd*
Step-5 - start raid devices
Because there are filesystems on /dev/hda1, /dev/hda2 and /dev/hda3 it is necessary to force the start of the raid device.
# mkraid --really-force /dev/md2
You can check the completion progress by cat'ing the /proc/mdstat file. It shows you status of the raid device and percentage left to sync.
Again this step can take quite some time (in the order of hours) so be patient.
Continue with / and /boot
# mkraid --really-force /dev/md1
# mkraid --really-force /dev/md0
The md driver syncs one device at a time.
Step-6 - resize filesystem
When we created the raid device, the physical partion became slightly smaller because a second superblock is stored at the end of the partition.
If you reboot the system now, the reboot will fail with an error indicating the superblock is corrupt.
Resize them prior to the reboot
You will be required to fsck each of the md devices except the swap device. The -f flag is required to force fsck to check a clean filesystem.
This will generate the same error about inconsistent sizes and possibly corrupted superblock.Say N to 'Abort?'.
# e2fsck -f /dev/md0
# e2fsck -f /dev/md1
# resize2fs /dev/md0
# resize2fs /dev/md1
Check again to be sure. Should be no errors now.
# e2fsck -f /dev/md0
# e2fsck -f /dev/md1
Remake swap space
# mkswap -c /dev/md2
Step-7 - Reboot and viola.
# reboot
4 Replies
1878 Views