[Dovecot] OT - small hd recommendation
kerem.erciyes at gmail.com
Fri Sep 2 10:17:29 EEST 2011
At least, rather than Seagate AS series or some "green" series try
using Seagate ST.SV series SATA HDDs, the 10$ difference is woth it.
They are certified for 7/24 operation and will not fail on you as
quickly. And they perform a little bit faster.
On Fri, Sep 2, 2011 at 8:55 AM, Spyros Tsiolis <stsiol at yahoo.co.uk> wrote:
> Don't know anything on RAID 10 with four disks, but I agree with the two-disk scenario.
> "I merely function as a channel that filters
> music through the chaos of noise"
> - Vangelis
> From: Thomas Harold <thomas-lists at nybeta.com>
> To: dovecot at dovecot.org
> Sent: Friday, 2 September 2011, 3:23
> Subject: Re: [Dovecot] OT - small hd recommendation
> On 9/1/2011 12:48 PM, Daniel L. Miller wrote:
>> Given my extensive requirements - I haven't yet filled my existing 320GB
>> - size isn't a big deal. Am I actually deriving much benefit from 4-disk
>> RAID10 using 160GB discs - vs a 2-4 disc 1TB RAID1 array?
> A pair of RAID-1 mirrors:
> - easy to deal with
> - you can attempt to manually balance load between the two arrays (storage on one pair, indexes and mail queue on other pair)
> - disks can be pulled and taken to another machine and read one by one
> - slightly harder to screw up (but both setups die if the wrong 2 disks fail)
> RAID-10 over 4 disks:
> - generally faster seeks
> - generally faster read/write speeds due to striping
> - generally the better choice for performance
> - a bit harder to bury the disks vs a pair of mirrors
> - lets you have a bigger partition
> - all the eggs in a single array
> If you're having performance problems on the existing RAID-10, your only real choices are to throw more spindles at it (move to a 6 or 8 disk RAID-10 w/ a hot-spare disk), throw faster spindles at it (10k/15k SAS), or move to SSD.
> So, if you think you can manually balance the needs of the system, you could try a pair of independent mirrors. But if you want less hassle, stick with the RAID-10.
> (And look into a tool like "atop" which can be run in the terminal and does a decent job of showing you whether the CPU/DISK is overly busy.)
Kerem Erciyes - Sistem Danismani
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