Andreas Micklei wrote:
Am Montag, 7. Mai 2007 schrieb Ruslan Sivak:
I've just installed the system as follows
Raid1 for /boot with 2 spares (200mb) raid0 for swap (1GB) raid6 for / (10GB)
NEVER EVER use raid0 for swap if you want reliability. If one drive fails the virtual memory gets corrupted and the machine will crash horribly (tm). Besides creating sepearte swap partitions on different physical discs will give you the same kind of performance, so using striping on a swap parition is kind useless for gaining performance.
I suggest using raid-1 or raid-6 for swap, so the machine can stay up if one drive fails.
Interesting thing... I build the following set up:
/boot on raid1 swap on raid0 / on raid6 /data on 2 lvm raid1's.
I shut down and plucked out one of the drives (3rd one I believe). Booted back up, everything was fine. Even swap (I think). I, rebooted, put in the old drive, hot added the partitions and everything rebuilt beautifully. (again not sure about swap).
I decided to run one more test. I plucked out the first (boot) drive. Upon reboot, I got greeted by GRUB all over the screen. Upon booting into rescue mode, it couldn't find any partitions. I was able to mount boot, and it let me recreate the raid1 partitions, but no luck with raid6. This is the second time that this has happened. Am I doing' something wrong? Seems when I pluck out the first drive, the drive letters shift (since sda is missing, sdb becomes sda, sdc becomes sdb and sdd becomes sdc).
What's the proper repair method for a raid6 in this case? Or should I just avoid raid6, and put / on 2 an LVM of 2 raid1's? Any way to set up interleaving (although testing raid1 vs raid10 with hdparm -t gives only marginal performance improvement).
Russ