undoing zfs deduplication

[Freddie Cash]

On Wed, Aug 8, 2012 at 9:08 AM, Brian Gold <bgold at simons-rock.edu> wrote:
>> Yes, that is the only option for "un-deduping" a filesystem.
>>
>> zfs send/recv from the deduped filesystem to one with dedup=off.  Then delete the deduped filesystem.
>>
>> Note:  a "zfs destroy" will use a lot of RAM as it has to go through an update all the DDT entries.  You may have to manually delete
>> individual snapshots, and then manually delete individual directories in the filesystem, before destroying the actual filesystem.  You
>> may run into a situation where you don't have enough RAM/ARC to destroy a deduped filesystem.
>>
>> --
>> Freddie Cash
>> fjwcash at gmail.com
>
> From what I've read so far, it looks like a "zfs send -R" would send the filesystem and all of the snapshots I've made. So would something like this work to move the duped filesystem and all of its snapshots over to a new undeduped filesystem: "zfs send -R backup/duped | zfs receive -duv backup/deduped" ?

Yes.  That will create a new filesystem and snapshots of the non-deduped data.

You would still have to delete the deduped filesystem, though, to
clear out the DDT and remove the extra RAM requirements of dedupe.


-- 
Freddie Cash
fjwcash at gmail.com