Subject: Re: FFSv1 performance on large filesystems
To: None <tech-perform@NetBSD.org, tech-kern@NetBSD.org>
From: Matthias Scheler <tron@zhadum.de>
List: tech-kern
Date: 03/04/2005 21:12:18
On Fri, Mar 04, 2005 at 08:36:32PM +0000, Matthias Scheler wrote:
> > >> dd if=/dev/zero of=test.img bs=1024k count=256
> > > 256+0 records in
> > > 256+0 records out
> > > 268435456 bytes transferred in 5.739 secs (46773907 bytes/sec)
> > How much memory do you have in this machine?
> 
> 2GB
> 
> > 256MB isn't a very large dataset.
> 
> Yes, but the other machine has 1GB, too. So if buffering would affect
> this the other machine would achieve the same performance. And 46MB/Sec
> reassembles the raw disk performance quite good.

I've repeated test with 4GB just to be sure:

> dd if=/dev/zero bs=1024k count=4096 of=/export/scratch/tron/test.img
4096+0 records in
4096+0 records out
4294967296 bytes transferred in 101.291 secs (42402259 bytes/sec)

The performance didn't change much as you can see.

	Kind regards

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