[OpenIndiana-discuss] OI151a8 free space reporting

[Jim Klimov]

On 2013-11-14 01:41, jason matthews wrote:
>
>
> zfs list is reporting the number you are interested in.
>
> zpool list essentially reports raw data which isn't particularly useful for capacity planning.

...And some of the discrepancies (between logically available and
physically allocated data counts) are due to:

1) RAIDZ Parity - not-yet-allocated parity sectors don't count in
zpool, but do count as (smaller) available logical data in zfs list.

2) Reservations, such as for volumes and for default volume snapshot
reservations (allowing to rewrite all of the volume) - this space is
not available to other datasets (including volume root), but some or
none or all of this may be allocated as physical data.

3) 1/64 of the pool size is AFAIK reserved for internal housekeeping.



In one of our cases this sums up to a largish difference:

# df -h /pond
Filesystem             size   used  avail capacity  Mounted on
pond                   8.0T    34K   174G     1%    /pond

# zfs list pond
NAME   USED  AVAIL  REFER  MOUNTPOINT
pond  7.85T   174G  34.3K  /pond

# zpool list pond
NAME   SIZE   USED  AVAIL    CAP  HEALTH  ALTROOT
pond  10.2T  9.37T   845G    91%  ONLINE  -

HTH,
//Jim

PS: Don't start new threads by replying to older unrelated emails ;)