Bryan Tong Minh schrieb:
On Sat, Jan 17, 2009 at 10:30 AM, Daniel Kinzler
<daniel(a)brightbyte.de>
wrote:
Tripling space requirements seems a bit of
overkill. Maybe there's a
smarter solution. Ideas?
ZFS snapshots?
Hm, to quote the relevant section from wikipedia:
An advantage of copy-on-write is that when ZFS writes
new data, the blocks
containing the old data can be retained, allowing a snapshot version of the
file system to be maintained. ZFS snapshots are created very quickly, since
all the data composing the snapshot is already stored; they are also space
efficient, since any unchanged data is shared among the file system and its
snapshots.
Writeable snapshots ("clones") can also be created, resulting in two
independent file systems that share a set of blocks. As changes are made to
any of the clone file systems, new data blocks are created to reflect those
changes, but any unchanged blocks continue to be shared, no matter how many
clones exist.
So... this means we can have the two-backup-stages solution i suggested, without
wasting space, because the unchanged data is shared by between tween the copies?
That would be perfect!
-- daniel