Theodore Tso <tytso <at> mit.edu> writes: > On Sun, Jul 27, 2008 at 04:54:41PM -0600, Eric Anopolsky wrote: > > On Sun, 2008-07-27 at 01:49 -0700, postrishi wrote: > > > > > > I want to know that has any work been done to port the Zfs features to > > > ext2/3 > > > > Did you know that ZFS is available for Linux? > > ZFS is available in a FUSE filesystem. As a userspace filesystem, it > means a huge number of context switches to get data between the disk, > to the kernel, to the FUSE userspace, back to the kernel, and to the > process trying to access the ZFS file. Transferring 4 kB from a commodity disk (disk seek + rotational delay + transfer) takes usually between 100-4,000 usec. Two context switches take about 2 usec, i.e. only 2-0.05% of the full data transfer time. In other words, there isn't really time for huge number of context switches because most of the time is spent waiting for the disk. > That's not going to be high performance. I did also an in memory test on a T9300@xxx, with disk I/O completely eliminated. Results: tmpfs: 975 MB/sec ntfs-3g: 889 MB/sec (note, this FUSE driver is not optimized yet) ext3: 675 MB/sec > For someone who wants to migrate from Solaris to Linux, > it might be useful, but I'm not sure you would really want to use a > ZFS/FUSE implementation in production. It seems the problem is that the only active ZFS-FUSE developer was hired by SUN and since then not much (visible) is happening. Regards, Szaka -- NTFS-3G: http://ntfs-3g.org -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
