On Thu, 2007-08-30 at 13:57 -0500, Eric Sandeen wrote: > Christoph Hellwig wrote: > > On Thu, Aug 30, 2007 at 05:07:46PM +1000, Nathan Scott wrote: > >> To improve metadata performance, you have many options with XFS (which > >> ones are useful depends on the type of metadata workload) - you can try > >> a v2 format log, and mount with "-o logbsize=256k", try increasing the > >> directory block size (e.g. mkfs.xfs -nsize=16k, etc), and also the log > >> size (mkfs.xfs -lsize=XXXXXXb). > > > > Okay, these suggestions are one too often now. v2 log and large logs/log > > buffers are the almost universal suggestions, and we really need to make > > these defaults. XFS is already the laughing stock of the Linux community > > due to it's absurdely bad default settings. > > Agreed on reevaluating the defaults, Christoph! > > barrier seems to hurt badly on xfs, too. Note: barrier is off by > default on ext[34], so if you want apples to apples there, you need to > change one or the other filesystem's mount options. If your write cache > is safe (battery backed?) you may as well turn barriers off. I'm not > sure offhand who will react more poorly to an evaporating write cache > (with no barriers), ext4 or xfs...
I didn't compare the safety of the three filesystems, but I did have disk caches disabled and only battery-backed caches enabled. Do you need barriers without volatile caches? Most people benchmark ext3 with data=writeback which is unsafe. I used ordered (the default). I think if you look at all the features, zfs is theoretically the most safe filesystem. But in practice, who knows? -jwb _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
