[ILUG] Dell PERCs and Linux

[Paul Kelly]

Paul Kelly wrote:
> I've got software RAID 5 running on a SPARC Classic (50MHz MicroSPARC)
> with three 4GB disks plugged into the same onboard SCSI bus (ESP, 10MHz
> narrow). Each disk has about 3GB dedicated to /dev/md0 and the rest in
> some form of non-RAID partition (swap, root, usr). The RAID partitions
> are all at the end of the disk which is generally a bit slower. The
> machine is unloaded and has 64MB RAM.

> The way I see it, even on this diminutive hardware, RAID5 is marginally
> ahead of where RAID1 would be and certainly no slower. I'll see if I can
> sic bonnie on the box later.

Bonnie results are in. RAID5:
              -------Sequential Output-------- ---Sequential Input-- --Random--
              -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
Machine    MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU  /sec %CPU
SPARC-Cl  100   559 89.6  3334 41.5  1754 48.5   304 98.2  4734 57.0 165.1 17.4


Single partition:
              -------Sequential Output-------- ---Sequential Input-- --Random--
              -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
Machine    MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU  /sec %CPU
SPARC-Cl  100   552 96.1  3060 80.2  1457 63.1   295 96.5  4046 65.7 118.1 12.4

A clear, if slight, win for RAID 5.

Paul.