[linux-lvm] Paralell IO performance with LVM and XFS

[Patrick Caulfield]

On Thu, Jan 17, 2002 at 01:56:39PM +0100, Russell Coker wrote:
> On Thu, 17 Jan 2002 13:29, Miguel Angel de Vega wrote:
> > I've a Dual P2 450 with a Disk Array with 4 scsi disks with XFS.
> > With one single disc I've 10 Mb/s reading and writing, so I think that if I
> > stripe all disc of the array, it can give me 4x10Mb = 40Mb/s more or less,
> > but I only gets 10 Mg/s!!
> 
> Striping across 4 disks will never give you 4* the throughput of 1 disk, but 
> you would hope for double the throughput.

A graph of some tests I did using bonnie++ and striping on fibre-channel disks
is online at http://www.cix.co.uk/~tykepenguin/stripetests.png

The most obvious bottleneck there was the actually FC interface which ran
out of capacity at 3 stripes.

patrick