ZFS MFC heads down

[Dillon Kass]

On 5/21/09 4:15 PM, Kip Macy wrote:
> Your snapshots are using two thirds of your used capacity. 'df' only
> knows about the mounted file system.
>
> Cheers,
> Kip
>
>    
On that subject, if anyone isn't aware this version of zfs has nicer 
space accounting.

you should check out the output of
zfs list -o space

SUPER AWESOME HUH!?

unfortunately the fancy new space accounting only works on datasets 
created on a pool supporting it, so all of us who upgraded our pools 
will not see any output.

for example

NAME                AVAIL   USED  USEDSNAP  USEDDS  USEDREFRESERV  USEDCHILD
rpool/ROOT/snv_107  8.86G  3.80G         -       -              -          -

however you can just create a new dataset with zfs create to take 
advantage of the new space accounting. then you'll get real output like

NAME                AVAIL   USED  USEDSNAP  USEDDS  USEDREFRESERV  USEDCHILD
phoenix/rsync/cifs  70.2G   272G      212G   59.3G              0          0

I can easily see here that I have 212G of snapshots for this dataset.

I just thought I would throw that out there for anyone who didn't know 
about it yet.