On Jul 13, 2005 17:12 -0700, Jeffrey W. Baker wrote: > I'm setting up a new file server and I just can't seem to get the > expected performance from ext3. Unfortunately I'm stuck with ext3 due > to my use of Lustre. So I'm hoping you dear readers will send me some > tips for increasing ext3 performance. > > The system is using an Areca hardware raid controller with 5 7200RPM > SATA disks. The RAID controller has 128MB of cache and the disks each > have 8MB. The cache is write-back. The system is Linux 2.6.12 on amd64 > with 1GB system memory. > > Using bonnie++ with a 10GB fileset, in MB/s: > > ext3 jfs xfs > Read 112 188 141 > Write 97 157 167 > Rewrite 51 71 60 > > These number were obtained using the mkfs defaults for all filesystems > and the deadline scheduler. As you can see JFS is kicking butt on this > test. One thing that is important for Lustre is performance of EAs. See http://samba.org/~tridge/xattr_results/ for a comparison. Lustre uses large inodes (-I 256 or larger) to store the EAs efficiently. > Next I used pgbench to test parallel random I/O. pgbench has > configurable number of clients and transactions per client, and can > change the size of its database. I used a database of 100 million > tuples (scale factor 1000). I times 100,000 transactions on each > filesystem, with 10 and 100 clients per run. Figures are in > transactions per second. > > ext3 jfs xfs > 10 Clients 55 81 68 > 100 Clients 61 100 64 > > Here XFS is not substantially faster but JFS continues to lead. > > JFS is roughly 60% faster than ext3 on pgbench and 40-70% faster on > bonnie++ linear I/O. This is a bit surprising, I've never heard JFS as a leader in many performance tests. Is pgbench at all related to dbench? The problem with dbench is that for cases where the filesystem does no IO at all it reports a best result. In real life the data has to make it to disk at some point. See http://sudhaa.com/~benchmark/ext3/newtiobenchresults.ext3gold/newtiobench/newtiobench.html for a comparison of ext3, xfs, jfs in the mode that Lustre runs in (specifically column 7, 14, 18). > Are there any tunables that I might want to adjust to get better > performance from ext3? Try creating your ext3 filesystem with a larger journal, as Lustre does: mkfs -J size=400 ... size is in MB, 400 might be excessive for your setup - I'd be interested in hearing where the "sweet spot" is for journal size. The latest e2fsprogs use 128MB as the largest default size (up from 32MB) for large filesystems. Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc. _______________________________________________ Ext3-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/ext3-users
