[Dovecot] Indexes to MLC-SSD

[Ed W]

On 27/10/2011 03:36, Stan Hoeppner wrote:
> On 10/26/2011 4:13 PM, Patrick Westenberg wrote:
>> Hi all,
>>
>> is anyone on this list who dares/dared to store his index files on a
>> MLC-SSD?
> I have not.  But I can tell you that a 32GB Corsair MLC SSD in my
> workstation died after 4 months of laughably light duty.  It had nothing
> to do with cell life but low product quality.  This was my first foray
> into SSD.  The RMA replacement is still kickin after 2 months,
> thankfully.  I'm holding my breath...
>
> Scanning the reviews on Newegg shows early MLC SSD failures across most
> brands, early being a year or less.  Some models/sizes are worse than
> others.  OCZ has a good reputation overall, but reviews show some of
> their models to be grenades.
>
> Thus, if you were to put indexes on SSD, you should strongly consider
> using a mirrored pair.
>

I don't think you are saying that the advice varies here compared with
HDDs?  I do agree that some SSDs are showing very early failures, but
it's only a tweak to the probability parameter compared with any other
storage medium.  They ALL fail at some point, and generally well within
the life of the rest of the server.  Some kind of failure planning is
necessary

Caveat the potentially higher failures vs HDDs I don't see any reason
why an SSD shouldn't work well? (even more so if you are using maildir
where indexes can be regenerated).

More interestingly: for small sizes like 32GB, has anyone played with
the "compressed ram with backing store" thing in newer kernels (that I
forget the name of now). I think it's been marketed for swap files, but
assuming I got the theory it could be used as a ram drive with slow
writeback to permanent storage?

Good luck

Ed W