Subject: Re: RAID: which level to use? (documentation slightly lacking)
To: None <firstname.lastname@example.org>
From: Greg Oster <email@example.com>
Date: 04/22/1999 16:13:15
Thor Lancelot Simon writes:
> But something is terribly wrong with RAIDframe's mirroring code. Its
> striping (RAID 0) code is only about 5-10% slower than our old 'ccd'
> device, but a mirror of two 7200RPM SCSI disks for me writes only at about
> 20-40KB/sec! I don't consider that useful.
Wowzers!!! That's brutal!! Can you send me (privately) a copy of your
RAID config files, dmesg, and anything else you might think is relevant?
(e.g. how you measured the 20-40KB/sec.)
I just whipped up a RAID1 on my test box (A P133 w/ 32MB of RAM, using a
pair of 1GB IBM 0662S12's on a single FastNarrow NCR SCSI controller in
this case) and Bonnie gives me:
-------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
rizzo 500 1565 47.7 2217 8.3 1217 8.0 2564 85.9 2933 10.2 43.5 6.1
There's no way my junky 3MB/sec 1GB SCSI drives should be outperforming
decent 7200RPM SCSI drives.... :-(