From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from postfix4-1.free.fr (postfix4-1.free.fr [213.228.0.62]) by mail.linbit.com (LINBIT Mail Daemon) with ESMTP id 0B93D14E73 for ; Wed, 3 Aug 2005 14:05:29 +0200 (CEST) Received: from computone.varlin (nor75-14-81-57-126-177.fbx.proxad.net [81.57.126.177]) by postfix4-1.free.fr (Postfix) with ESMTP id A4964319E78 for ; Wed, 3 Aug 2005 14:05:24 +0200 (CEST) Date: Wed, 3 Aug 2005 14:15:30 +0200 From: Antoine Calando To: drbd-dev@lists.linbit.com Message-ID: <20050803141530.52037016@computone.varlin> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: [Drbd-dev] GFS over DRBD: It looks promising! List-Id: Coordination of development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hello, I've done some test with the last version of DRBD (rev 1912, 0.8-pre1) and Red Hat GFS, and I got some interesting results. I set up a primary/primary DRBD link on two nodes. I created a GFS partition with gulm lock on /dev/drbd0, I mounted it on both nodes and I tried some basic tests: it worked! I can copy and create files (I tried with a few megas), and they appear on the other node without any problem. I tried then to run a bonnie++ bench on one node, but I had a kernel freeze :v( (without any interesting log on the crashed node) I do some other tests with bonnie++, GFS and DRBD, to find where the problem is: - GFS in local/single mode with bonnie++: it works - GFS in local/gulm lock mode (2 mounts) with bonnie++: it works (by the way, it is quite fast) - ext3 on DRBD (rev 1912) in primary/secondary with bonnie++: it works. - GFS with gulm lock on DRBD (1912) primary/secondary, with bd_claim disabled. GFS is mounted r/w on primary node, and ro on secondary node. It freezes when I launch bonnie++. - GFS with no lock on DRBD (1912) primary/secondary (GFS only mounted on primary): it reboots after a few seconds with bonnie++. - Same test with DRBD 0.7.11: same result, with a delay of a few minutes. It seems that DRBD can not manage heavy I/O with GFS, but I don't know why. Here are some detailed instructions if somebody else want to try without spending hours and hours with poor documentation ;): I get GFS from here http://sourceware.org/cluster/ I had much problems with packages, so the best is to use cvs code. I used STABLE branch. # cvs -d :pserver:cvs@sources.redhat.com:/cvs/cluster checkout -r STABLE cluster There was some errors during the make. I had to do some make/"make install" several times in order to install completely GFS. (following instructions may be inacurate, I don't have gfs on the machine I'm using now, it's just what I remember since yesterday) To create a gfs partition in nolock mode (pointless, just for tests): # gfs_mkfs -p lock_nolock -t cluster_name:fs_name -j 1 /dev/disk_device To mount it: # mount -t gfs /dev/disk_device /mnt/gfs0 To create a gfs partiton for 2 nodes with gulm lock on primary DRBD device: # gfs_mkfs -p lock_gulm -t cluster_name:fs_name -j 2 /dev/drbd_device Gulm lock server must be started before mounting partition on both nodes: node1# lock_gulm -n cluster_name -s node1 -v All (node1 is gulm server) node2# lock_gulm -n cluster_name -s node1 -v All GFS over DRBD can then be mounted on each node. Happy testing and thanks to the DRBD team for this great piece of software! Antoine