Bill Moore wrote:
On Wed, Jul 19, 2006 at 03:10:00AM +0200, [EMAIL PROTECTED] wrote:
So how many of the 128 bits of the blockpointer are used for things
other than to point where the block is?
128 *bits*? What filesystem have you been using? :) We've got
luxury-class block pointers that are 128 *bytes*. We get away with it
because we also have big data blocks to go with them. In your typical
mixed-data storage pool, about 1-2% total (including all the block
pointers) is ZFS metadata, everything else is real user data. The
breakdown of a block pointer is roughly:
3 x 128 bits - DVAs (up to 3-way ditto blocks)
1 x 64 bits - misc. properties
1 x 64 bits - block birth
1 x 64 bits - fill count
1 x 256 bits - checksum
3 x 64 bits - future growth (some to be used by encryption)
Of course this can change (grow) in the future if the ZFS version number
changes?
For both the encryption and checksum use, it wouldn't be unreasonable to
see the requirements here expand (maybe double?) sometime in the near
future.
Darren
_______________________________________________
zfs-discuss mailing list
zfs-discuss@opensolaris.org
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
