On Friday 03 March 2006 06:23 am, Scott Silva wrote:
RAID 1 partition: md0 = 80GB (or whatever the useable total is)
Then include md0 in VolGroup00 and create your logical volumes.
LV0 = 300MB (/boot) LV1 = 500MB (swap) LV2 = 9.2GB (/) LV3 = 70GB (/home)
This way everything is mirrored and everything is in one VG. If you need more space, add another pair of mirrored drives and add the new mirrored device into VolGroup00. Then you can use the space to expand whichever filesystem needs it. I would also advise following the previous poster's advice and leaving a few GB unused so that you aren't forced to add more drives immediately when LV2 fills up faster than you expected.
Ok guys, I have done it just like you suggesting (and also just like what the RHEL System Administrator Guide says).
But you can't boot from a /boot partition in LVM. It needs to be either a physical partition or a raid1 array.
That's why I make this partition scheme: sda1 and sdb1 = 300, mounted as /boot, raided as RAID 1 -> md0 sda2 and sdb2 = 79GB, raided as, raided as RAID 1 -> md1, then LVMed as VolGroup00, then added LV /, /home, and swap as needed.
By the way, looks like the grub bug on Raid 1 is no longer exist on Centos 4.2. It correctly installs bootloader on both drives.
I then tested the disaster plan, I unplugged one drive, got email from mdadm that the raid was in degraded mode.
Plugged the drive back in, adding it again: mdadm /dev/md0 --add /dev/sda1 mdadm /dev/md1 --add /dev/sda2
And the RAID is rebuild :)
I love Centos :) Thank you very much.