On Wed, 12 Jan 2000, Peter Palfrader aka Weasel wrote:
> Hi Gurus!
>
> I've set up raid 0 on my box half a year ago and back then everything
> worked fine. Recently I made a benchmark again and was pretty
> disappointed by the results I got.
>
> I have a P II 400, 128 Megs of RAM, and 2 IBM DRVS 09V (10,000 RPM;
> 6.3 ms; 9.1 Gig) on a AHA 2940 U2W. Those harddisks are the only
> devices on this SCSI controller.
>
>
> On a single hard disk on a partition at the very end of the hd (ext2)
> bonnie reports the following:
> -------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
> 500 6068 85.0 6784 9.0 4196 11.4 6418 79.9 17241 15.0 104.5 1.0
>
>
> Now a raid0 system should IMHO be while not twice as fast at least
> considerable faster (at least with sequention input) but bonnie
> reports:
> -------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
> 500 6203 87.1 12428 16.3 7231 19.9 6443 80.4 25411 24.7 122.3 2.3
>
> tested on a 2 partition raid 0 with both partitions being located at
> the very start of the hard disks.
>
> When I set this up 5 or 6 months ago it was considerable faster
> (approx. 35 Megs/sec). A friend of mine has a similar setup and also
> gets about 35 Megs/sec.
>
If you haven't changed your kernel or disk setup, the only
thing which comes to my mind is that before your disk was empty
and the bonnie test file fit in nicely in order. Now
if your disk is full, there isn't so much sequential blocks free,
so it will be allocated a little here and there resulting
a little poorer performance.
But if you just made the array then i am puzzled.
If you really want to have a fast system (more than just
for bonnie) pay close attention to seektimes.
>
> I'm running a plain 2.2.14 but the results are no different than with
> a 2.2.10 or 2.2.12.
>
>
> Do you have any pointers what might be wrong/what I could try to
> improve speed?
>
If i understood correctly you use plain 2.2.14 without newest
raidpatches ?
-- Mika <[EMAIL PROTECTED]>
