[Dovecot] OT - small hd recommendation
patrickdk at patrickdk.com
Wed Aug 31 03:51:41 EEST 2011
SATA 1 vs SATA 3 won't change the seek performance of the drive,
unless your stay fully within the drives cache.
Only 2 things affect how many iops you can get from a drive. The
physical diameter and the speed. You can affect the physical diameter
of the drive by selecting how much of the drive you use, like only
using 200gigs out of a 500gig drive.
If you do opt for raid6, that would be a huge cpu overhead, and if you
stick with 4 drives, not worth it, every write would hit atleast 3
drives then, instead of just two they do currently, with no gain of
Quoting "Daniel L. Miller" <dmiller at amfes.com>:
> 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?
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