From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx3.redhat.com (mx3.redhat.com [172.16.48.32]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id l8PLQc7B029254 for ; Tue, 25 Sep 2007 17:26:38 -0400 Received: from shuttlerun.csg.stercomm.com (scidalsmtp02.csg.stercomm.com [204.214.3.25]) by mx3.redhat.com (8.13.1/8.13.1) with ESMTP id l8PLQc4K014707 for ; Tue, 25 Sep 2007 17:26:38 -0400 Message-ID: <46F97D06.60306@stercomm.com> Date: Tue, 25 Sep 2007 16:26:30 -0500 From: Chris Cox MIME-Version: 1.0 Subject: Re: [linux-lvm] LVM2 striping or md raid0 References: <5cbd03f56b69e61e1407530930bb5939@memcpy.com> In-Reply-To: Content-Transfer-Encoding: 7bit Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" To: LVM general discussion and development Kelly Byrd wrote: > > > On Sat, 22 Sep 2007 18:36:41 -0700, Kelly Byrd > wrote: >> Two questions really: >> >> I'm going to use lvm to partition up 4 equal size partitions. >> I can either use the md driver to RAID0 them the make /dev/md0 >> my PV, or just use the 4 partitions as PVs and stripe across >> them. >> >> How does lvm2 striping compare with md's RAID0 as far as speed? >> I don't quite get how it stripes on chunk sizes smaller than >> a PE, but a 4MB stripe size seems crazy. >> >> Finally, what's the tuning advice for LVM2 striping? I usually >> create my RAID0 or RAID5 with 128k chunk sizes, is it similar >> for LVM2 striping? >> >> > > anyone? This is merely my own opinion, but md was designed to be THE software raid mechanism. So, my preference would be to establish a RAID md device and make that into a PV. Of course, I don't believe in non-RAID (i.e. RAID0) anyhow. Maybe someone else will chime in on this one. -- Chris Cox Sr. Unix Sys Admin