[SunHELP] UFS logging + RAID-5

[Brian Hechinger]

> Any advantage or disadvantage to running UFS logging on top of
> a RAID-5 filesystem?

RAID has no understanding of the filesystem.  the only thing RAID protects you
against is hardware failure.  if you have RAID and do an ungraceful poweroff of
your box, your UFS will still be hosed, but at least you'll know it will be 
there even if a disk takes a dump.

the disadvantages are the same as with a single non-RAID disk.  slight 
performance hit, but in my opinion, the advantages far outweigh the 
disadvantages.

if you are building an IO intensive system (database comes to mind) then you
could always use the UFS logging that comes with SDS (since you are already 
using SDS) which gives you the added ability to put your logs on a different
splindle which negates the performance hit.

-brian