[ILUG] Linux SMP on Xeons

[Wesley Darlington]

Hi,

On Thu, Jun 15, 2000 at 01:05:43PM +0100, Paul Jakma wrote:
> On Thu, 15 Jun 2000, Paul Trainor wrote:
> > AMI Megaraid should do the job.
> what sort of performance do they give? from what i've seen on linux-raid
> they're dreadfully dreadfully slow, esp. at RAID5.

I recommend the AMI megaraid 1500 elite. They *rock*. 128MB battery backed
cache. Dell call it a "PERC 2/DC". It came in a Dell 2450 (which I
recommend for your mail box, Colm, btw. Even two cpus is overkill for
outgoing mail - but about right/not enough if you're delivering mail
locally, doing imap and/or even hosting webmail on the same box.)

I have done quite a few benchmarks on the 2450 with 1500raid...
Machine with 2GB ram, four 18GB 10k disks as a raid5 array with 128kB
"bits" (*). LVM. Then ext2 filesystems async, 4kB blocks, stride=32,
bonnie++ results with dataset of 4GB...

Version 0.99e       ------Sequential Output------ --Sequential Input- --Random-
                    -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine          MB K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
Unknown        4096  9789  99 30189  20 12476  21  9536  95 42929  30   5.4   0
                    ------Sequential Create------ --------Random Create--------
                    -Create-- --Stat--- -Delete-- -Create-- --Stat--- -Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
                 30   196  99   642  99  6978 100   197  99   826 100   796  97
Unknown,4096,9789,99,30189,20,12476,21,9536,95,42929,30,
+5.4,0,30,196,99,642,99,6978,100,197,99,826,100,796,97

All the other AMI raid cards I've seen are good only for landfill. This
one kicks bottom. :-)

Wesley.

(*) Sorry, AMI's documentation doesn't make it clear whether it's 128kB
over $n$ disks or per disk. ie. chunks or stripes. Like I care.