Right. Another difference to be aware of is that ZFS reports the total space consumed, including space for metadata -- typically around 1%. Traditional filesystems like ufs and ext2 preallocate metadata and don't count it as using space. I don't know how reiserfs does its bookkeeping, but I wouldn't be surprised if it followed that model.
Jeff On Mon, Mar 30, 2009 at 02:57:31PM -0400, Brad Plecs wrote: > > I've run into this too... I believe the issue is that the block > size/allocation unit size in ZFS is much larger than the default size > on older filesystems (ufs, ext2, ext3). > > The result is that if you have lots of small files smaller than the > block size, they take up more total space on the filesystem because > they occupy at least the block size amount. > > See the 'recordsize' ZFS filesystem property, though re-reading the > man pages, I'm not 100% sure that tuning this property will have the > intended effect. > > BP > > > > I rsynced an 11gb pile of data from a remote linux machine to a zfs > > filesystem with compression turned on. > > > > The data appears to have grown in size rather than been compressed. > > > > Many, even most of the files are formats that are already compressed, > > such as mpg jpg avi and several others. But also many text files > > (*.html) are in there. So didn't expect much compression but also > > didn't expect the size to grow. > > > > I realize these are different filesystems that may report > > differently. Reiserfs on the linux machine and zfs on osol. > > > > in bytes: > > > > Osol:11542196307 > > linux:11525114469 > > ================= > > 17081838 > > > > Or (If I got the math right) about 16.29 MB bigger on the zfs side > > with compression on. > > > > > > _______________________________________________ > > zfs-discuss mailing list > > zfs-discuss@opensolaris.org > > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss > > -- > bpl...@cs.umd.edu > _______________________________________________ > 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
