[Toolserver-l] New hardware ordered

[Daniel Kinzler]

Bryan Tong Minh schrieb:
> On Sat, Jan 17, 2009 at 10:30 AM, Daniel Kinzler <daniel at 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