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