Managing ZFS Storage Pool Properties

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To manage ZFS pool properties, you use the following commands:

zpool get all pool – Lists all the properties of the pool with their corresponding values.
zpool get property pool – Lists the specified property of the pool with its corresponding value.
zpool set property=value pool – Assigns a value to the pool's specified property.

If you attempt to set a pool property on a pool that is full, a message similar to the following is displayed:

# zpool set autoreplace=on system1
cannot set property for 'system1': out of space

For information on preventing pool space capacity problems, see Recommended Oracle Solaris ZFS Practices.

Table 2 ZFS Pool Property Descriptions

Property Name	Type	Default Value	Description
`allocated`	String	N/A	Read-only value that identifies the amount of storage space within the pool that has been physically allocated.
`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 in the following situations: when you are examining an unknown pool, if the mount points cannot be trusted, or in an alternate boot environment where the typical paths are not valid.
`autoreplace`	Boolean	`off`	Controls automatic device replacement. If set to `off`, you must initiate device replacement 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 property abbreviation is `replace`.
`bootfs`	Boolean	N/A	Identifies the default bootable file system for the root pool. This property is typically set by the installation programs.
`cachefile`	String	N/A	Controls where pool configuration information is cached. All pools in the cache are automatically imported when the system boots. However, installation and clustering environments might require this information to be cached in a different location so that pools are not automatically imported. You can set this property to cache pool configuration information in a different location. This information can be imported later by using the `zpool import` `–c` command. For most ZFS configurations, this property is not used.
`capacity`	Number	N/A	Read-only value that identifies the percentage of pool space used. The property abbreviation is `cap`.
`dedupditto`	String	N/A	Sets a threshold for the reference count for a deduped block. If the count goes above the threshold, another ditto copy of the block is stored automatically.
`dedupratio`	String	N/A	Read-only deduplication ratio achieved for a pool, expressed as a multiplier.
`delegation`	Boolean	`on`	Controls whether a nonprivileged user can be granted access permissions that are defined for a file system. For more information, see Oracle Solaris ZFS Delegated Administration.
`failmode`	String	`wait`	Controls the system behavior if a catastrophic pool failure occurs. This condition is typically a result of a loss of connectivity to the underlying storage device or devices or a failure of all devices within the pool. The behavior of such an event is determined by one of the following values: `wait` – Blocks all I/O requests to the pool until device connectivity is restored and the errors are cleared by using the `zpool clear` command. In this state, I/O operations to the pool are blocked but read operations might succeed. A pool remains in the `wait` state until the device issue is resolved. `continue` – Returns an EIO error to any new write I/O requests but allows reads to any of the remaining healthy devices. Any write requests that have yet to be committed to disk are blocked. After the device is reconnected or replaced, the errors must be cleared with the `zpool clear` command. `panic` – Prints a message to the console and generates a system crash dump.
`free`	String	N/A	Read-only value that identifies the number of blocks within the pool that are not allocated.
`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`, `SUSPENDED`, `REMOVED`, or `UNAVAIL`.
`listshares`	String	off	Controls whether share information in this pool is displayed with the `zfs list` command. The default value is `off`.
`listsnapshots`	String	off	Controls whether snapshot information that is associated with this pool is displayed with the `zfs list` command. If this property is disabled, you can display snapshot information with the `zfs list` `–t snapshot` command.
`readonly`	Boolean	off	Identifies whether a pool can be modified. This property is enabled only when a pool is has been imported in read-only mode. If enabled, any synchronous data that exists only in the intent log will not be accessible until the pool is re-imported in read-write mode.
`size`	Number	N/A	Read-only property that identifies the total size of the storage pool.
`version`	Number	N/A	Identifies the current on-disk version of the pool. The preferred method of updating pools is with the `zpool upgrade` command, although you can use this property when you need a specific version for backwards compatibility. You can set this property to any number between 1 and the current version reported by the `zpool upgrade` `–v` command.