Different sizes between zfs list and zpool list

[Jeremy Chadwick]

On Wed, May 05, 2010 at 04:44:32PM +0100, Tom Evans wrote:
> When looking at the size of a pool, this information can be got from
> both zpool list and zfs list:
> 
> > $ zfs list
> NAME                       USED  AVAIL  REFER  MOUNTPOINT
> tank                      5.69T   982G  36.5K  /tank
> 
> > $ zpool list
> NAME   SIZE   USED  AVAIL    CAP  HEALTH  ALTROOT
> tank  8.14T  6.86T  1.28T    84%  ONLINE  -
> 
> Why the different sizes?
> 
> The pool is a raidz of 6 x 1.5 TB drives.

Is the tank filesystem using compression?  "zfs get all" would help shed
some light here.

There is some variance in AVAIL on all of our systems, and I see
identical on Solaris 10.  My guess is (the equivalent of) parity of
raidz has something to do with it.

However, in the case of our systems, USED always matches between zfs
list and zpool list.

-- 
| Jeremy Chadwick                                   jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |