David wrote:
I have two devices mirrored which are partitioned like this:
Device Boot Start End Blocks Id System
/dev/sda1 * 63 30716279 15358108+ fd Linux raid
autodetect
/dev/sda2 30716280 71682029 20482875 fd Linux raid
autodetect
/dev/sda3 71682030 112647779 20482875 fd Linux raid
autodetect
/dev/sda4 112647780 156248189 21800205 5 Extended
/dev/sda5 112647843 122881184 5116671 82 Linux swap /
Solaris
/dev/sda6 122881248 156248189 16683471 fd Linux raid
autodetect
My aim was to have the two swap partitions both mounted, no RAID (as I
didn't see any benefit to that, but if I'm wrong then I'd appreciate
being told!). However it seems that sda5 seems to be recognised as an
md anyway at boot, so swapon does not work correctly. When
initialising the partitions with mkswap, the RAID array is confused
and refuses to boot until the superblocks are fixed.
If you use RAID0 on an array it will be faster (usually) than just
partitions, but any process with swapped pages will crash if you lose
either drive. With RAID1 operation will be more reliable but no faster.
If you use RAID10 the array will be faster and more reliable, but most
recovery CDs don't know about RAID10 swap. Any reliable swap will also
have the array size smaller than the sum of the partitions (you knew that).
--
bill davidsen <davidsen@xxxxxxx>
CTO TMR Associates, Inc
Doing interesting things with small computers since 1979
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