zpool-initialize.8

ZPOOL-INITIALIZE(8) System Manager's Manual ZPOOL-INITIALIZE(8)

zpool-initialize — write to unallocated regions of ZFS storage pool

zpool initialize [-c|-s |-u] [-w] [-z] -a|pool [device]…

Begins initializing by writing to all unallocated regions on the specified devices, or all eligible devices in the pool if no individual devices are specified. Only leaf data or log devices may be initialized. By default a non-zero pattern is written; see -z to write zeroes instead.

, --all
Begin, cancel, suspend initializing on all pools.
, --cancel
Cancel initializing on the specified devices, or all eligible devices if none are specified. If one or more target devices are invalid or are not currently being initialized, the command will fail and no cancellation will occur on any device.
, --suspend
Suspend initializing on the specified devices, or all eligible devices if none are specified. If one or more target devices are invalid or are not currently being initialized, the command will fail and no suspension will occur on any device. Initializing can then be resumed by running zpool initialize with no flags on the relevant target devices.
, --uninit
Clears the initialization state on the specified devices, or all eligible devices if none are specified. If the devices are being actively initialized the command will fail. After being cleared zpool initialize with no flags can be used to re-initialize all unallocated regions on the relevant target devices.
, --wait
Wait until the devices have finished initializing before returning.
, --zero
Write zeroes to the unallocated regions instead of the default non-zero pattern. This is useful for reclaiming space on thinly provisioned backing storage which does not support TRIM. If the backing storage supports TRIM, zpool-trim(8) is typically the more efficient way to return space to it. The chosen value is recorded per device, so a run that is suspended and later resumed keeps writing zeroes.

zpool-add(8), zpool-attach(8), zpool-create(8), zpool-online(8), zpool-replace(8), zpool-trim(8)

July 12, 2026 Debian