On Thu, Oct 23, 2008 at 8:15 AM, Felix Miata <mrmazda@ij.net> wrote:
On 2008/10/23 02:48 (GMT-0500) David C. Rankin composed:
The Software RAID penalty -- virtually non-existent as far as hdparm is concerned.
The results are astounding when you think what has happened in just a few years...
More like 9 years (UDMA33 to SATA300), in which of late the law has been breaking down.
Here's my results from an old HP NetServer E60 Dual P3/500Mhz, 256MB RAM: Stand alone SCSI drive: /dev/sda: Timing cached reads: 258 MB in 2.00 seconds = 129.00 MB/sec Timing buffered disk reads: 92 MB in 3.04 seconds = 30.26 MB/sec Software Raid 5(on disks 2-4) /dev/sdb: Timing cached reads: 258 MB in 2.00 seconds = 129.00 MB/sec Timing buffered disk reads: 90 MB in 3.02 seconds = 29.84 MB/sec As you can see, the software RAID 5 was slightly slower than accessing the standalone disk. The drives are basically limited by the fact that I am currently using the onboard SCSI controller, which is only 40MB/s. sda and sdb are Fujitsu MAJ3091MP(10k rpm, U160, 4k buffer) and sdc and sdd are HP A 68-F305(Which I think are similar specs). However, since this machine is a data backup server, speed isn't really important because everything sent to it comes in over 100Mb ethernet right now. If I move it to gigabit, then I may move it to a faster PCI SCSI card..... -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org