[Dovecot] OT - small hd recommendation

[Daniel L. Miller]

A little OT - but I've seen a few opinions voiced here by various admins 
and I'd like to benefit.

Currently running a single combined server for multiple operations - 
fileserver, mailserver, webserver, virtual server, and whatever else 
pops up.  Current incarnation of the machine, after the last rebuild, is 
an AMD Opteron 4180 with a Supermicro MB using ATI SB700 chipset - which 
means it supports SATA 3.0.

Current storage is one o/s drive, and a 4-drive RAID10 array.  The 
RAID10 is using the Linux softraid via mdadm.  The drives are Seagates - 
ST3160811AS.  So it's 320GB of storage, and SATA 1.5.

I'm seeing some warnings & errors in my logs & dmesg - and Google tells 
me this can the result of several factors, including the hard drives.  I 
haven't seen any SMART warnings as yet - but I am getting a little 
nervous and thinking about upgrading the storage.

At this time, I'm just interested in recommendations for hard drives & 
partitioning strategy.  At the time I created the RAID10 array - I was 
still in the early stages of learning these technologies (not that I 
know that much more now!) so I probably didn't take advantage of any of 
the advanced settings such as stripe size, cluster size, etc.  I am 
using XFS.

As part of the potential upgrade, I'm considering changing to RAID6 - 
seems a bit more efficient use of space.  I see no reason for SSD - I 
think a set of reasonable 7200rpm drives should be just fine.  What I 
don't know is, compared to my current 4 drive RAID10 with SATA 1.5, 
would even a single SATA 3 drive be comparable in terms of seek 
performance?  Should I stick with the RAID-10?
-- 
Daniel