From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick Caulfield Subject: Re: [linux-lvm] Paralell IO performance with LVM and XFS Message-Id: <20020117175832.GL1066@tykepenguin.com> References: <200201171229.g0HCTVe10111@localhost.localdomain> <20020117125640.35CF032FDE6@lyta.coker.com.au> <20020117152130.GG1066@tykepenguin.com> <20020117173959.5BF1F35FA9E@lyta.coker.com.au> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20020117173959.5BF1F35FA9E@lyta.coker.com.au> Sender: linux-lvm-admin@sistina.com Errors-To: linux-lvm-admin@sistina.com Reply-To: linux-lvm@sistina.com List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: Date: Thu Jan 17 11:59:02 2002 List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-lvm@sistina.com On Thu, Jan 17, 2002 at 06:39:58PM +0100, Russell Coker wrote: > On Thu, 17 Jan 2002 16:21, Patrick Caulfield wrote: > > On Thu, Jan 17, 2002 at 01:56:39PM +0100, Russell Coker wrote: > > > 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/stripetest.png > > Firstly, I suggest that you skip the per-char tests when graphing such > things, it's generally not very interesting and just clutters the graph. > > Next the seeks, block-io, and create/delete test results belong on different > graphs because the Y axis measures different things, and because it needs > different scales. Yeah, I just graphed the whole output - I only did it for my own interest really, it's not meant to be an official test or especially meaningful. I just thought it might be interesting. The only reason it's still on my web site is that I forgot to remove it. > Finally what graphing program did you use? Err...I'd rather not say... > > The most obvious bottleneck there was the actually FC interface which ran > > out of capacity at 3 stripes. > > Why are you so certain that it's the FC interface at fault? The FC interface > should be able to do more than 60MB/s. I don't suppose I am that certain to be honest but I had so much trouble with the Linux drivers for this card that at the time I was prepared to blame everything from Global Warming downwards on it. patrick