Hi,
There have been several requests (from more than one
person, or just
from one person) for 15k spindle drives. Is that a universal
consensus? I find it hard to imagine that faster drives is really
pertinent, because just about any problem that can be solved with
faster drives can be solved better with more ram?
In theory: yes. But if more RAM or faster UPM are better should be
tested, this belongs to the kind of application.
Don't you/we have a dealer who allows to test this on a new server?
This could help us to proof our suggestions instead of speculating.
RAID 10? That's what geoffrin had, and it was
sweet. But RAID 5
would give more disk space, right?
Yes. RAID 10 gives you 50% of the hard disc capacity while RAID 5 gives
you 66%. That sounds not too much difference but it is :-) 8 drives of
150 GB -> 1200 GB gross capacity. RAID 10: 600 GB net capacity. RAID 5:
about 792 GB net capacity. That's more than one extra hard drive for
"free".
RAID 10 is a bit faster than RAID 5.
I would recommend two or three spare hard drives, not only one. If
one's dying in the RAID and the only hotspare drives begins to rebuild
the data (which could take quite a long time) and before someone is
able to replace the broken one a second hard drive gets corrupted then
the RAID is lost. This is of no importance if someone is 24/7 near the
server room.
What are our disk requirements for the db server?
Let's be generous
with ourselves here. But, also let's think about whether disk space
needs might in some cases be better handled by a big slow cheap SATA
storage server?
SATA-RAIDs are as fast as SCSI-RAIDs concerning the sustained read
benchmarks but not when accessing random data - this is what I measured
for our firm here.
BTW: I don't know siliconmechanics (and can't reach their website now)
but I was very content with Fujitsu-Siemens Primergy servers. We're
running a lot of them. No, I don't have stock options or something like
that from them and we don't sell them (we don't sell something computer
related at all).
YMMV.
Sorry for my bad English, I'm not a native speaker.
Regards
Götz