Re: Hardware for a database server

Erwin Brandstetter said:

> Controller / Hard Discs:
> RAID 5 with 4+ discs including a hot spare. But SCSI or SATA?
> I am undecided on this. Until about a year ago, I would have said SCSI,
> period. But I have read of SATA RAIDs for entry-level-servers doing
> quite well and Linux dealing with it ever more smoothly. ([1], [2])
> So I wonder if it is still a good decission to spend 3 times the money
> per gigabyte on SCSI?
> And do 3ware Controllers still have the best driver support under
> Linux?
> Any harddisks known to be especially apt for databases (hi I/O load
> ..)?
>
> Power supply:
> Secured with UPS, auto-shutdown before power fails, so do I need my
> RAID controller battery-backed still?

> RAM:
> As much as the motherboard will bear. 4 GB probably. This seems the
> easyest point to decide on. Correct? DDR SDRAM PC333 or PC400?

It doesn't seem like 4GB is even remotely necessary.  I guess it depends on
whether you will hit the 5GB size before the machine is upgraded.  There
really isn't any point in having RAM larger than the size of the database,
that's for sure.

We've had very good luck with the proliant raid controllers.  I'm sure there
are other brands now that are better,  but ease of recovery is a very
important consideration.  There have been some worst case nightmares realized
with certain brands in the (distant) past that I know of.

As far as cost per GB on scsi is concerned, I would suggest putting things in
perspective.  For $150 you can get a 36gb drive, which is less than a third of
what you can get in terms of capacity/$ for ata.  But if you use four of the
36's you are going to have at least an order of magnitude more disk space than
you actually need for this server.  In general, I'd rather have the tried and
true for what I really need.

Also depending on your uptime requirements, you might want to look at hot
pluggable drives.  Power supply redundancy is reasonable now as well.

Best regards,

Jim Wilson