Hardware RAID Level & Performance

[Rob Mueller]

> Umem cards seem a preferred choice, since there's a driver for them in the
> standard linux kernel ... But they're kinda hard to find these days, so 
> Rob
> Mueller found these in our last discussion:
> http://www.curtisssd.com/products/drives/nitrofc/
>
> Rob, do you mind sharing some expiriences with them?

Currently we only use umem and have good experiences. Seem to be stable, 
fast and just work. Unfortunately I don't think umem are selling to the 
public anymore, or at least selling only as is, no support. They seem to be 
concentrating on wholesale corporate sales (eg to companies like netapp that 
incorporate them into their products, etc). One other issue with umem, since 
it's a PCI card, if you want a failover type system, then it's not going to 
be easy, you'll have to regularly sync your data from one to the other and 
live with some out of date-ness problems with a switchover, or possibly data 
corruption issues :(

We haven't tried the above nitro drives, though they look promising, albeit 
quite expensive. On the other hand, by spending a bit more upfront to get 
high IO on your mailboxes.db/seen dbs/quota dbs, you'll be able to scale to 
a lot more mailboxes in the future on a particular machine. Hmmm Fibre 
connectors as well, so it could be held in an external container connected 
to your 2 failover machines.

If anyone invests in one of these, I'd been keen to hear feedback and 
experiences with them.

Rob

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