Subject: Re: RAIDframe performance revisited
To: None <tech-perform@NetBSD.org>
From: Matthias Scheler <tron@zhadum.de>
List: tech-perform
Date: 07/07/2005 11:47:05
On Wed, Jul 06, 2005 at 01:36:43PM +0100, Matthias Scheler wrote:
> On this benchmark RAIDframe is suddenly a lot slower than the physical disks.
> What could cause this? Ideas which come to my mind are:
[...]
> - different FFS block layout on the physical disks vs. the RAIDframe volume
>   because they report a different geometry ...

I've now changed the disklabel of "raid0" to match the one of my
physical disks:

tron@lyssa:~>disklabel raid0
disklabel: Invalid signature in mbr record 0
# /dev/rraid0d:
type: RAID
disk: raid
label: fictitious
flags:
bytes/sector: 512
sectors/track: 63
tracks/cylinder: 15
sectors/cylinder: 945
cylinders: 179747
total sectors: 169861760
rpm: 7200
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0           # microseconds
track-to-track seek: 0  # microseconds
drivedata: 0 

4 partitions:
#        size    offset     fstype [fsize bsize cpg/sgs]
 c: 169860915         0     unused      0     0        # (Cyl.      0 - 179746)
 d: 169860915         0     4.2BSD   1024  8192 46672  # (Cyl.      0 - 179746)

But extracting the source tar archives still takes twice as long as on
the physical disks.

	Kind regards

-- 
Matthias Scheler                                  http://scheler.de/~matthias/