Dell and SSD drives

[Stephen John Smoogen]

On Wed, Jan 28, 2009 at 5:04 PM, Adam Nielsen <adam.nielsen at uq.edu.au> wrote:
>> I am looking at our mail servers and trying to get some disk IO
>> contentions down. I would like to know if people have used SSD's in a
>> Linux environment. I am looking at an SSD over a ramdisk for
>> persistence of storage in case of reboots. What I would like to do is
>> put in 2 SSD's into a 2950 and have them deal with the malware and
>> spam scanning directories as that seems to be the contention points.
>
> When you say "reboots" do you mean unexpected hardware resets, or
> intentional shutdown+restart?  Unexpected hardware resets will almost always
> cause some amount of data loss, but if you want persistence over controlled
> restarts then I agree with the other posts here that putting as much RAM in
> the machine as you can will provide a decent speed increase, as Linux will
> use all the extra RAM for disk caching.  In the case of a mail server,
> messages could arrive and be retrieved by clients without ever touching the
> disk - assuming of course clients check their mail before it gets flushed
> out to disk - the more mail you have passing through the machine (and the
> less RAM), the sooner this will happen.
>
> Persistence over reboots here wouldn't be a problem, as the disk cache will
> get written out before shut down.
>
> Perhaps another alternative is one of those i-RAM type cards, which let you
> attach battery-backed RAM to a SATA port.  I think they'd be in the same
> price range as an SSD, only they're a *lot* faster (apparently the SATA port
> is the bottleneck, so ~300MB/sec read/write.)  I think they'd certainly be
> the fastest option, however I'm not sure whether you can get them in decent
> sizes (maybe 8-16GB?)  The battery would also guarantee persistence over
> reboots and (short) shut downs.

Ahh thats exactly what I was looking for. Thankyou. Do you know what
the class of 'disks' these are called?


-- 
Stephen J Smoogen. -- BSD/GNU/Linux
How far that little candle throws his beams! So shines a good deed
in a naughty world. = Shakespeare. "The Merchant of Venice"