On Tue, 26 May 2009, Scott Marlowe wrote:
> Plus if you only need 4 drives or something, you can do pretty well with
> a Dell with the RAID controller turned to JBOD and letting the linux
> kernel do the RAID work.
I think most of the apps I'm considering would be OK with 4 drives and a
useful write cache. The usual hosted configurations are only 1 or 2 and
no usable cache, which really limits what you can do with the server
before you run into a disk bottleneck. My rule of thumb is that any
single core will be satisfied as long as you've got at least 4 disks to
feed it, since it's hard for one process to use more than a couple of
hundred MB/s for doing mostly sequential work. Obviously random access is
much easier to get disk-bound, where you have to throw a lot more disks at
it.
It wouldn't surprise me to find it's impossible to get an optimal setup of
8+ disks from any hosting provider. Wasn't asking for "great" DB
performance though, just "good".
--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD