u235sentinel wrote:
> I'm curious if anyone has had any experiences (good and bad) using
> Postgres on Dell PowerEdge servers.
Poweredge is a brandname that describes every single server Dell has
sold since about 15 years ago, maybe more. I had a Poweredge that was
a dual 600Mhz pentium-III w/ 1GB ram and 4 x 72gb scsi disks.
> My manager and I are looking at replacing a Sun x4540 server with a
> Dell server connected to a disk subsystem (or two). We're looking at
> the R710 servers connected to an MD1220 I believe (I'd have to look
> again at the quote).
>
why are you looking at replacing it? you go onto say its working great.
> The concern we have is our 4540 has a 2TB database which is working
> great. The server has 48 hard drives (250 gig drives) in RAID 10
> across 6 disk controllers. A couple HBA controllers connected to a
> couple dozen disks may be slower (though dell assures us it will be
> faster than our Sun box).
of course they do, they want to sell you their iorn... do they have
benchmarks of their proposed configuration vs a x4540 doing the sorts of
tasks you require to back up their claim? The MD1220 is connected to
the host with a single X4 SAS cable.
btw, the x4540 has each disk on its own SATA channel, 8 channels to the
SATA chip, and each SATA chip on a PCI-E x4 bus, so it has sufficient IO
backplane bandwidth to keep all 48 disks busy at once. ZFS is
extremely good at this. The Sun Thumpers have been benchmarked with
rather high IOPS numbers, that few other sorts of systems can sustain in
real world tests.
you can make ZFS on a thumper even faster by using a couple SSDs for the
ZIL logs.
> I thought I'd toss this out and see if anyone has any thoughts on
> this. I'm inclined to try it. The drives quoted are 15k drives and
> the PERC controller has cache vs. the Sun controllers have no cache
> AFAIK.
Solaris and ZFS use main memory as the cache. main memory is faster
than any memory out on an IO controller.
>
> BTW, in the next few months I believe we're be hitting the 2.5-3 TB
> size for our database. The tables are partitioned which helps a lot.
> Performance would be a problem otherwise with that much data I think :-)
upgrade your thumper to 1TB drives and go to town. They -should- be
Sun approved drives, however, as there is all sorts of room for
sketchiness using the wrong SATA disks.