Managing ZFS Storage Pool Properties

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

# zpool get all u03 NAME PROPERTY VALUE SOURCE u03 size 68G - u03 capacity 0% - u03 altroot - default u03 health ONLINE - u03 guid 601891032394735745 default u03 version 22 default u03 bootfs - default u03 delegation on default u03 autoreplace off default u03 cachefile - default u03 failmode wait default u03 listsnapshots on default u03 autoexpand off default u03 free 68.0G - u03 allocated 76.5K -

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

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

Table 4–1 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 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, device replacement must be initiated 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 property abbreviation is replace.
bootfs	Boolean	N/A	Identifies the default bootable dataset for the root pool. This property is typically set by the installation and upgrade 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.
delegation	Boolean	on	Controls whether a nonprivileged user can be granted access permissions that are defined for a dataset. For more information, see Chapter 9, 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, FAULTED, OFFLINE, REMOVED, or UNAVAIL.
listsnapshots	String	on	Controls whether snapshot information that is associated with this pool is displayed with the zfs list command. If this property is disabled, snapshot information can be displayed with the zfs list -t snapshot command.
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 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.