Managing ZFS Storage Pool Properties

You can use the zpool get command to display pool property information. For example:

# zpool get all tank2
NAME   PROPERTY     VALUE       SOURCE
tank2  size         33.8G       -
tank2  used         158K        -
tank2  available    33.7G       -
tank2  capacity     0%          -
tank2  altroot      -           default
tank2  health       ONLINE      -
tank2  guid         8032621780930948264  -
tank2  version      8           default
tank2  bootfs       -           default
tank2  delegation   on          default
tank2  autoreplace  off         default
tank2  temporary    off         default
tank2  failmode     wait        default

Storage pool properties can be set with the zpool set command. For example:

# zpool set autoreplace=on tank
# zpool get autoreplace tank
NAME  PROPERTY     VALUE    SOURCE
tank  autoreplace  on       default

Table 4-1 ZFS Pool Property Descriptions

Property Name	Type	Default Value	Description
`altroot`	String	off	Identifies an alternate root directory. If set, this directory is prepended to any mount points within the pool. This property can be used when examining an unknown pool, if the mount points cannot be trusted, or in an alternate boot environment, where the typical paths are not valid. Setting this property implies that the `temporary` property is also set.
`available`	Number	N/A	Read-only value that identifies the amount of storage that is available within the pool. This property can also be referred to by its shortened column name, `avail`.
`autoreplace`	Boolean	`off`	Controls automatic device replacement. If set to off, device replacement must be initiated by the administrator by using the `zpool` `replace` command. If set to on, any new device, found in the same physical location as a device that previously belonged to the pool, is automatically formatted and replaced. The default behavior is off. This property can also be referred to by its shortened column name, `replace`.
`bootfs`	Boolean	N/A	Identifies the default bootable dataset for the root pool. This property is expected to be set mainly by the installation and upgrade programs.
`capacity`	Number	N/A	Read-only value that identifies the percentage of pool space used. This property can also be referred to by its shortened column name, `cap`.
`delegation`	Boolean	`on`	Controls whether a non-privileged user can be granted access permissions that are defined for the dataset. For more information, see Chapter 8, ZFS Delegated Administration.
`guid`	String	N/A	Read-only property that identifies the unique identifier for the pool.
`health`	String	N/A	Read-only property that identifies the current health of the pool, as either ONLINE, DEGRADED, FAULTED, OFFLINE, REMOVED, or UNAVAIL .
size	Number	N/A	Read-only property that identifies the total size of the storage pool.
used	Number	N/A	Read-only property that identifies the amount of storage space used within the pool.
temporary	Boolean	off	Controls whether the pool is available temporarily. By default, all pools are persistent, and are automatically opened when the system is rebooted. Setting this property to `on` causes the pool to exist only while the system is up. If the system is rebooted, the pool has to be manually imported by using the `zpool import` command. Setting this property is helpful when using pools on removable media, where the devices might not be present when the system reboots. This property can also be referred to by its shortened column name, `temp`.
version	Number	N/A	Identifies the current on-disk version of the pool. The value of this property can be increased, but never decreased. The preferred method of updating pools is with the `zpool upgrade` command, although this property can be used when a specific version is needed for backwards compatibility. This property can be set to any number between 1 and the current version reported by the `zpool upgrade` `-v` command. The `current` value is an alias for the latest supported version.