On Fri, Mar 13, 2009 at 5:41 AM, Mark Johnson <[email protected]> wrote: >> So ext3 on zvol is faster than zfs? Is it the effect of compression=on >> and if=/dev/zero? > > zero is easy to compress, so probably not a good example :-)
Yeah, but zfs and zvol should handle the compression (and also checksum) the same way right? Which makes me wonder why on earth did ext3 on zvol get such good performance. > > I'm not sure what effect compression might have other than > that, but if your using zfs in dom0, you should limit the > size of the arc. > > echo "set zfs:zfs_arc_max = 0x10000000" >> /etc/system Will do. I'll try again with uncompressed zvol as well. > > If your using a disk file (vs a zvol) on a zfs filesystem, > you should set the recordsize for that fs to 8k. zvols > already default to 8k. > > zfs set recordsize=8k rpool/guests > > I'm only using zvols. Why 8k, not 4k? AFAIK the default cluster size for NTFS is 8k, as is ext3's default block size. Either way, since I'm testing using dd with 1M blocksize, shouldn't the block size be less relevant? Regards, Fajar _______________________________________________ xen-discuss mailing list [email protected]
