[horde] Bottleneck ? CPU or HDisk IO or RAM

[Eric Jon Rostetter]

Quoting Linux Advocate <linuxhousedn at yahoo.com>:

> perc raid controller, pci-e. a raid 5 config.

I recently tested a Perc 6/i with SATA and RAID-10 was by far the best
performance for simulated mail applications like IMAP.  RAID-5 was
a lot slower.  You might want to consider this...

Yes, disk numbers are an issue (you might use 1 disk for system and read-only
stuff, 1 for hot spare, 4 for raid-10, for example).

You can also gain performance via partitioning the drives into a smaller,
first partition and striping that partitions with raid-5 instead of striping
the whole disk.  Then use the remaining partition for another less-used
raid-5 (backups, etc).  The idea is you reduce seek time on the first
partition to speed things up, and also provide improved caching, though
this means the other partition(s) must be lightly used or else seeking
to them and caching from them will put you right back to where you started.
This would be an advanced topic... :)

But again, you only say perc, not which perc, so your mileage may vary.

-- 
Eric Rostetter
The Department of Physics
The University of Texas at Austin

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