[OmniOS-discuss] zfs diskusage

[Tobias Oetiker]

Today we were out of diskspace on one of our pools ... a few removed
snapshots later all is fine, except that I find that I don't realy
understand the numbers ... can anyone elighten me?

# zpool list fast
NAME   SIZE  ALLOC   FREE  EXPANDSZ    CAP  DEDUP  HEALTH  ALTROOT
fast  4.34T  1.74T  2.61T         -    39%  1.22x  ONLINE  -

# zfs list fast
NAME   USED  AVAIL  REFER  MOUNTPOINT
fast  2.59T   716G  78.5K  /fast

Why does the 'zpool list' claim that 2.61T is free (61%)
while 'zfs list' sees 716G free (27%)

I know there is raidz2 and compression so the numbers  don't match
up, but I don't understand why the ratio is so different between
the two.

I checked on other filesystems and there the view from zpool and
zfs look much more similar.

cheers
tobi

ps. the dedup ratio is a leftover from a time when I tried dedup.

$ zpool get all fast
NAME  PROPERTY                       VALUE                          SOURCE
fast  size                           4.34T                          -
fast  capacity                       39%                            -
fast  altroot                        -                              default
fast  health                         ONLINE                         -
fast  guid                           16524146496274345089           default
fast  version                        -                              default
fast  bootfs                         -                              default
fast  delegation                     on                             default
fast  autoreplace                    off                            default
fast  cachefile                      -                              default
fast  failmode                       wait                           default
fast  listsnapshots                  off                            default
fast  autoexpand                     off                            default
fast  dedupditto                     0                              default
fast  dedupratio                     1.22x                          -
fast  free                           2.61T                          -
fast  allocated                      1.74T                          -
fast  readonly                       off                            -
fast  comment                        -                              default
fast  expandsize                     0                              -
fast  freeing                        0                              default
fast  feature at async_destroy          enabled                        local
fast  feature at empty_bpobj            active                         local
fast  feature at lz4_compress           active                         local
fast  feature at multi_vdev_crash_dump  enabled                        local
fast  feature at spacemap_histogram     active                         local
fast  feature at extensible_dataset     enabled                        local

$ zfs get all fast
NAME  PROPERTY              VALUE                  SOURCE
fast  type                  filesystem             -
fast  creation              Fri Jan  4 17:19 2013  -
fast  used                  2.59T                  -
fast  available             716G                   -
fast  referenced            78.5K                  -
fast  compressratio         1.81x                  -
fast  mounted               yes                    -
fast  quota                 none                   default
fast  reservation           none                   default
fast  recordsize            128K                   default
fast  mountpoint            /fast                  default
fast  sharenfs              off                    default
fast  checksum              on                     default
fast  compression           lz4                    local
fast  atime                 on                     default
fast  devices               on                     default
fast  exec                  on                     default
fast  setuid                on                     default
fast  readonly              off                    default
fast  zoned                 off                    default
fast  snapdir               hidden                 default
fast  aclmode               discard                default
fast  aclinherit            restricted             default
fast  canmount              on                     default
fast  xattr                 on                     default
fast  copies                1                      default
fast  version               5                      -
fast  utf8only              off                    -
fast  normalization         none                   -
fast  casesensitivity       sensitive              -
fast  vscan                 off                    default
fast  nbmand                off                    default
fast  sharesmb              off                    default
fast  refquota              none                   default
fast  refreservation        none                   default
fast  primarycache          all                    default
fast  secondarycache        all                    default
fast  usedbysnapshots       0                      -
fast  usedbydataset         78.5K                  -
fast  usedbychildren        2.59T                  -
fast  usedbyrefreservation  0                      -
fast  logbias               latency                default
fast  dedup                 off                    local
fast  mlslabel              none                   default
fast  sync                  standard               default
fast  refcompressratio      1.00x                  -
fast  written               78.5K                  -
fast  logicalused           2.22T                  -
fast  logicalreferenced     19.5K                  -

-- 
Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland
www.oetiker.ch tobi at oetiker.ch +41 62 775 9902