|From:||Karl Denninger <karl(at)denninger(dot)net>|
|To:||Laszlo Nagy <gandalf(at)shopzeus(dot)com>|
|Subject:||Re: SSD + RAID|
|Views:||Raw Message | Whole Thread | Download mbox | Resend email|
Laszlo Nagy wrote:
> I'm about to buy SSD drive(s) for a database. For decision making, I
> used this tech report:
> Here are my concerns:
> * I need at least 32GB disk space. So DRAM based SSD is not a real
> option. I would have to buy 8x4GB memory, costs a fortune. And
> then it would still not have redundancy.
> * I could buy two X25-E drives and have 32GB disk space, and some
> redundancy. This would cost about $1600, not counting the RAID
> controller. It is on the edge.
> * I could also buy many cheaper MLC SSD drives. They cost about
> $140. So even with 10 drives, I'm at $1400. I could put them in
> RAID6, have much more disk space (256GB), high redundancy and
> POSSIBLY good read/write speed. Of course then I need to buy a
> good RAID controller.
> My question is about the last option. Are there any good RAID cards
> that are optimized (or can be optimized) for SSD drives? Do any of you
> have experience in using many cheaper SSD drives? Is it a bad idea?
> Thank you,
Note that some RAID controllers (3Ware in particular) refuse to
recognize the MLC drives, in particular, they act as if the OCZ Vertex
series do not exist when connected.
I don't know what they're looking for (perhaps some indication that
actual rotation is happening?) but this is a potential problem.... make
sure your adapter can talk to these things!
BTW I have done some benchmarking with Postgresql against these drives
and they are SMOKING fast.
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