On Wed, 21 Mar 2012, maillist reader wrote:
I read though that ZFS does not have a "defragmentation" tool, is this still the case? It would seem with such a performance difference between "sequential reads" and "random reads" for raidzN's, a defragmentation tool would be very high on ZFS's TODO list ;).
Zfs does not usually suffer significantly from fragmentation. To be clear, "random reads" means random file access and necessary head seeks. Any mechanical-based device will suffer from this and it is not specific to zfs.
Something which is specific to zfs is that within a zdev, a stripe must be read and written completely. Partial stripe reads are not supported since a full read is necessary in order to validate the block checksum.
Bob -- Bob Friesenhahn bfrie...@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
