Notes to Self

Alex Sokolsky's Notes on Computers and Programming

ZFS Dataset

From ZFS 101 “A ZFS dataset is roughly analogous to a standard, mounted filesystem”. Need it, e.g. to have ACLs.

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# zfs get all tank/downloads
NAME            PROPERTY                VALUE                   SOURCE
tank/downloads  type                    filesystem              -
tank/downloads  creation                Tue Nov  2 14:04 2021   -
tank/downloads  used                    5.15M                   -
tank/downloads  available               4.61T                   -
tank/downloads  referenced              5.15M                   -
tank/downloads  compressratio           1.21x                   -
tank/downloads  mounted                 yes                     -
tank/downloads  quota                   none                    default
tank/downloads  reservation             none                    default
tank/downloads  recordsize              128K                    default
tank/downloads  mountpoint              /mnt/tank/downloads     default
tank/downloads  sharenfs                off                     default
tank/downloads  checksum                sha512                  local
tank/downloads  compression             lz4                     inherited from tank
tank/downloads  atime                   off                     inherited from tank
tank/downloads  devices                 on                      default
tank/downloads  exec                    on                      default
tank/downloads  setuid                  on                      default
tank/downloads  readonly                off                     default
tank/downloads  zoned                   off                     default
tank/downloads  snapdir                 hidden                  default
tank/downloads  aclmode                 passthrough             local
tank/downloads  aclinherit              passthrough             inherited from tank
tank/downloads  createtxg               3020                    -
tank/downloads  canmount                on                      default
tank/downloads  xattr                   sa                      local
tank/downloads  copies                  1                       local
tank/downloads  version                 5                       -
tank/downloads  utf8only                off                     -
tank/downloads  normalization           none                    -
tank/downloads  casesensitivity         insensitive             -
tank/downloads  vscan                   off                     default
tank/downloads  nbmand                  off                     default
tank/downloads  sharesmb                off                     default
tank/downloads  refquota                none                    default
tank/downloads  refreservation          none                    default
tank/downloads  guid                    3495570787300485094     -
tank/downloads  primarycache            all                     default
tank/downloads  secondarycache          all                     default
tank/downloads  usedbysnapshots         0B                      -
tank/downloads  usedbydataset           5.15M                   -
tank/downloads  usedbychildren          0B                      -
tank/downloads  usedbyrefreservation    0B                      -
tank/downloads  logbias                 latency                 default
tank/downloads  objsetid                92                      -
tank/downloads  dedup                   off                     default
tank/downloads  mlslabel                none                    default
tank/downloads  sync                    disabled                inherited from tank
tank/downloads  dnodesize               legacy                  default
tank/downloads  refcompressratio        1.21x                   -
tank/downloads  written                 5.15M                   -
tank/downloads  logicalused             6.17M                   -
tank/downloads  logicalreferenced       6.17M                   -
tank/downloads  volmode                 default                 default
tank/downloads  filesystem_limit        none                    default
tank/downloads  snapshot_limit          none                    default
tank/downloads  filesystem_count        none                    default
tank/downloads  snapshot_count          none                    default
tank/downloads  snapdev                 hidden                  default
tank/downloads  acltype                 nfsv4                   default
tank/downloads  context                 none                    default
tank/downloads  fscontext               none                    default
tank/downloads  defcontext              none                    default
tank/downloads  rootcontext             none                    default
tank/downloads  relatime                on                      default
tank/downloads  redundant_metadata      all                     default
tank/downloads  overlay                 on                      default
tank/downloads  encryption              off                     default
tank/downloads  keylocation             none                    default
tank/downloads  keyformat               none                    default
tank/downloads  pbkdf2iters             0                       default
tank/downloads  special_small_blocks    0                       default
tank/downloads  org.truenas:managedby          local
tank/downloads  org.freebsd.ioc:active  yes                     inherited from tank

Manipulate Flags

Use zfs set, e.g., to turn compression on for the pool:

zfs set compression=lz4 POOLNAME

Create ZFS Dataset

Use zfs create:

zfs create -o aclinherit=passthrough -o aclmode=passthrough -o acltype=nfsv4 -o atime=off -o casesensitivity=sensitive -o xattr=sa btr/foo

For example:

> zpool status
  pool: btr
 state: ONLINE
  scan: scrub repaired 0B in 00:00:00 with 0 errors on Thu Jan  4 17:37:18 2024

	btr         ONLINE       0     0     0
	  mirror-0  ONLINE       0     0     0
	    sda1    ONLINE       0     0     0
	    sdb1    ONLINE       0     0     0

errors: No known data errors

  pool: tank
 state: ONLINE
  scan: scrub repaired 0B in 00:00:00 with 0 errors on Thu Jan  4 17:37:36 2024

	tank        ONLINE       0     0     0
	  mirror-0  ONLINE       0     0     0
	    sdc1    ONLINE       0     0     0
	    sdd1    ONLINE       0     0     0

errors: No known data errors

> sudo zfs create -o aclinherit=passthrough -o aclmode=passthrough -o acltype=nfsv4 -o atime=off -o casesensitivity=sensitive -o xattr=sa btr/foo
[sudo] password for alex:

> sudo zfs get all btr/foo
NAME     PROPERTY              VALUE                  SOURCE
btr/foo  type                  filesystem             -
btr/foo  creation              Sat Jan 13  9:11 2024  -
btr/foo  used                  24K                    -
btr/foo  available             108G                   -
btr/foo  referenced            24K                    -
btr/foo  compressratio         1.00x                  -
btr/foo  mounted               yes                    -
btr/foo  quota                 none                   default
btr/foo  reservation           none                   default
btr/foo  recordsize            128K                   default
btr/foo  mountpoint            /mnt/btr/foo           inherited from btr
btr/foo  sharenfs              off                    default
btr/foo  checksum              on                     default
btr/foo  compression           on                     default
btr/foo  atime                 off                    local
btr/foo  devices               on                     default
btr/foo  exec                  on                     default
btr/foo  setuid                on                     default
btr/foo  readonly              off                    default
btr/foo  zoned                 off                    default
btr/foo  snapdir               hidden                 default
btr/foo  aclmode               passthrough            local
btr/foo  aclinherit            passthrough            local
btr/foo  createtxg             146180                 -
btr/foo  canmount              on                     default
btr/foo  xattr                 sa                     local
btr/foo  copies                1                      default
btr/foo  version               5                      -
btr/foo  utf8only              off                    -
btr/foo  normalization         none                   -
btr/foo  casesensitivity       sensitive              -
btr/foo  vscan                 off                    default
btr/foo  nbmand                off                    default
btr/foo  sharesmb              off                    default
btr/foo  refquota              none                   default
btr/foo  refreservation        none                   default
btr/foo  guid                  14145355866866016782   -
btr/foo  primarycache          all                    default
btr/foo  secondarycache        all                    default
btr/foo  usedbysnapshots       0B                     -
btr/foo  usedbydataset         24K                    -
btr/foo  usedbychildren        0B                     -
btr/foo  usedbyrefreservation  0B                     -
btr/foo  logbias               latency                default
btr/foo  objsetid              903                    -
btr/foo  dedup                 off                    default
btr/foo  mlslabel              none                   default
btr/foo  sync                  standard               default
btr/foo  dnodesize             legacy                 default
btr/foo  refcompressratio      1.00x                  -
btr/foo  written               24K                    -
btr/foo  logicalused           12K                    -
btr/foo  logicalreferenced     12K                    -
btr/foo  volmode               default                default
btr/foo  filesystem_limit      none                   default
btr/foo  snapshot_limit        none                   default
btr/foo  filesystem_count      none                   default
btr/foo  snapshot_count        none                   default
btr/foo  snapdev               hidden                 default
btr/foo  acltype               nfsv4                  local
btr/foo  context               none                   default
btr/foo  fscontext             none                   default
btr/foo  defcontext            none                   default
btr/foo  rootcontext           none                   default
btr/foo  relatime              on                     default
btr/foo  redundant_metadata    all                    default
btr/foo  overlay               on                     default
btr/foo  encryption            off                    default
btr/foo  keylocation           none                   default
btr/foo  keyformat             none                   default
btr/foo  pbkdf2iters           0                      default
btr/foo  special_small_blocks  0                      default

Destroy ZFS Dataset

Use zfs destroy:

zfs destroy tank/foo