Hardware RAID Level & Performance

[Henrique de Moraes Holschuh]

On Tue, 15 Feb 2005, Jure Pe_ar wrote:
> On Tue, 15 Feb 2005 12:18:57 -0500
> Lee <lee at disinfo.com> wrote:
> 
> > What are the implication of raid 10 vs. raid 5 with cyrus? Are they 
> > significant? Does EXT3 play into the discussion?

1. Use 2.6.10+ ext3, with all hashing enabled
2. Use an external journal in a fast device (not the RAID5 array)

> Cyrus 2.3 CVS code enables you to split indexes and cyrus db files into
> their own partition. That's where most of the i/o activity is concentrated,
> so you only need to optimize that partition. The mail spool that remains can
> be raid5.

This is probably the best way to do it, especially if you have some
non-volatile solid-state disks around as it was suggested  in this list
sometime ago...

> Yes, ext3 does have its problems, depending on how many users and how big
> mailboxes you have. I'd recommend reiserfs.

I've heard bad things about reiserfs' capabilities to withstand
corruption *and* to be repaired later. Something that I'd take into account
when choosing the FS for the big spools.  But maybe reiserfs has non-joke
repair utilities these days...

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh
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