From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Dilger Message-Id: <200006051658.e55GwQx16588@webber.adilger.net> Subject: Re: [linux-lvm] performance problems Date: Mon, 5 Jun 2000 10:58:26 -0600 (MDT) MIME-Version: 1.0 Sender: owner-linux-lvm Errors-To: owner-linux-lvm List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Linux LVM mailing list Chris writes: > We are using LVM on a (hardware) RAID array and are > having some performance problems. File copying is > very slow and one of the guys using it reported that > untarring was very sluggish, and he got I/O errors. > Is this a known problem? I believe we are using 0.8i > and we are using 2.2.13 kernel. Any help would be > greatly appreciated. Have you been using LVM without problem before, or is this a brand new installation? If the speed problem is new (i.e. LVM has been installed and working well for a while), it may well be that you have a disk problem, and the RAID array is slow because it needs to do extra parity calculations for all I/O. Getting I/O errors is a bad sign, as LVM doesn't know anything about hardware RAID, it only knows there is a big disk beneath it. If it is a new LVM installation, it may be that you want to check the RAID stripe size/PE size/ext2 RAID stride are all set to reasonable multiples of each other for maximum 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