From mboxrd@z Thu Jan 1 00:00:00 1970 From: Herbert Poetzl Subject: Re: [linux-lvm] LVM on Raid 5 Performance? Message-ID: <20030519113159.GA23496@www.13thfloor.at> References: <92091C60D5E2B74CB77C1FDB84F5FA76F079@s99mail02.okdhs.org> <200305182148.27901.jason@oes.co.th> Mime-Version: 1.0 Content-Disposition: inline In-Reply-To: <200305182148.27901.jason@oes.co.th> 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: Mon May 19 06:31:02 2003 List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-lvm@sistina.com On Sun, May 18, 2003 at 09:48:27PM +0700, Jason H. Smith wrote: > I don't know if this answers your question, but maybe search the archives > for my posts a few months ago. On 2.4, there's a misfeature when using > LVM with RAID5. Basically, the two will cause your system not to cache > any data, and to sync to disk immediately, once you create a snapshot > volume. Apparently, this will be addressed in 2.6. hmm, I read about that, but I guess that's not what happens, because a) I do not use the snapshot feature, and b) the "raid5: switching cache buffer size" messages only appear if I access the md device directly ... > So if you want RAID5 and LVM, consider hardware acceleration. I guess I will choose not to use LVM on this system ... thanks, Herbert > HTH > > -- > GPG: 03EE 9EB8 E500 874A F509 7B95 9B9A 84A1 26E9 4F79 > http://www.ece.utexas.edu/~jhs/public_key.gpg > > _______________________________________________ > linux-lvm mailing list > linux-lvm@sistina.com > http://lists.sistina.com/mailman/listinfo/linux-lvm > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/