I would also suggest setting the recordsize property on the zvol when you create it to 4k, which is, I think, the native ext3 block size. If you don't do this and allow ZFS to use it's 128k default blocksize, then a 4k write from ext3 will turn into a 128k read/modify/write on the ZFS side. This could easily explain your performance issues.
Try this out and let us know what the results are. --Bill On Tue, Sep 11, 2007 at 11:49:40AM +1000, Joshua Goodall wrote: > I've been seeing read and write performance pathologies with Linux > ext3 over iSCSI to zvols, especially with small writes. Does running > a journalled filesystem to a zvol turn the block storage into swiss > cheese? I am considering serving ext3 journals (and possibly swap > too) off a raw, hardware-mirrored device. Before I do (and I'll > write up any results) I'd like to know if anyone tried/addressed > this already. > > The lack of tools to analyse ZFS fragmentation means I'm somewhat > in the dark, so I'm just likely to suck it and see. > > JG > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
