Skip navigation.

Admin Notes - Windows/Linux

Admin Notes - Windows/Linux

Windows 2000

Booting From Mirror After Primary Partition Is Lost

Boot.ini format explained

Changing Active Partition Can Make Your System Unbootable

Linux

http://www.tldp.org/HOWTO/Software-RAID-HOWTO.html

The raid config is stored in /etc/raidtab

Slow Resync

On RH8, the resynch is much slower than Win2000 because it will resynch the whole hard disk, not just the modified blocks. There is a faster raid driver, but i'm not confident enough to install it.

On crash, mirrors will resynch, with the original being raid disk 0, and the mirror being raid disk 1. This is very slow. To stop resync, read /etc/raidtab and then run:

raidsetfaulty <raid-device> <mirror-hard-disk-device>
eg. for mobydick (see raidtab below):

raidsetfaulty /dev/md0 /dev/hdb1

Later, in the evening, restart the raid resynch by:

raidhotremove /dev/md0 /dev/hdb1
raidhotadd /dev/md0 /dev/hdb1

Moby Dick raidtab


>> cat /etc/raidtab
raiddev             /dev/md0
raid-level                  1
nr-raid-disks               2
chunk-size                  64k
persistent-superblock       1
nr-spare-disks              0
    device          /dev/hda2
    raid-disk     0
    device          /dev/hdb1
    raid-disk     1

Linux Rescue

a. On crash and you cannot restart, then try reboot using Red Hat rescue CD. You will be prompted to enter a rescue command at the LILO prompt. Then it will go through part of the install process (to configure keyboard and language), so don't be too concerned that you are reinstalling). The rescue mode will then mount the original root file system at /mnt/sysimage. Now you can continue with repairs...

b. after mounting , view (cat) /mnt/sysimage/etc/fstab and /mnt/sysimage/etc/raidtab

c. run fsck -t [type from fstab] [/dev/? from fstab]

d. reboot from hard disk

e. After reboot, mirrors will resync. Use cat /proc/mdstat to monitor sync progress.