From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Andreas Dilger Message-Id: <200105151708.f4FH8NaR019248@webber.adilger.int> Subject: Re: [linux-lvm] LVM and *bad* performance (no striping) In-Reply-To: "from Urs Thuermann at May 15, 2001 01:46:15 pm" Date: Tue, 15 May 2001 11:08:22 -0600 (MDT) MIME-Version: 1.0 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: List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-lvm@sistina.com Urs writes: > Sorry, I hadn't time to test your patch earlier. I wanted to try it > yesterday but lvm-0.9.1-beta7 with your patch applied doesn't compile. Sorry, I must have missed some parts of the patch for the user-space tools. Even so, I don't think the patch will help. > I also did some tests with another hard disk drive. My previous tests > were with a IBM DCAS-34330W SCSI-U2W. I now did some tests with a NEC > DSE2100S SCSI2 drive. Again, LVM is much slower with the standard > 512 byte block size: One other person had a similar problem. It was because they were using PIO mode instead of DMA mode on their (IDE) drive. However, I see you are using a SCSI disk, so I don't know what to suggest... What SCSI controller are you using? > And am I really the only one who sees this? I would really be > interested to hear from some more people about performance for their > LVM. I have never seen more than a few percent difference between LVM and non-LVM performance. Cheers, Andreas -- Andreas Dilger \ "If a man ate a pound of pasta and a pound of antipasto, \ would they cancel out, leaving him still hungry?" http://www-mddsp.enel.ucalgary.ca/People/adilger/ -- Dogbert