Taking a Device Offline

You can take a device offline by using the zpool offline command. The device can be specified by path or by short name, if the device is a disk. For example:

# zpool offline tank c1t0d0
bringing device c1t0d0 offline

Keep the following points in mind when taking a device offline:

• You cannot take a pool offline to the point where it becomes faulted. For example, you cannot take offline two devices out of a raidz1 configuration, nor can you take offline a top-level virtual device.

  # zpool offline tank c1t0d0 cannot offline c1t0d0: no valid replicas

• By default, the offline state is persistent. The device remains offline when the system is rebooted.

  To temporarily take a device offline, use the zpool offline -t option. For example:

  # zpool offline -t tank c1t0d0 bringing device 'c1t0d0' offline

  When the system is rebooted, this device is automatically returned to the ONLINE state.

• When a device is taken offline, it is not detached from the storage pool. If you attempt to use the offlined device in another pool, even after the original pool is destroyed, you will see a message similar to the following:

  device is part of exported or potentially active ZFS pool. Please see zpool(1M)

  If you want to use the offlined device in another storage pool after destroying the original storage pool, first bring the device back online, then destroy the original storage pool.

  Another way to use a device from another storage pool if you want to keep the original storage pool is to replace the existing device in the original storage pool with another comparable device. For information about replacing devices, see Replacing Devices in a Storage Pool.

Offlined devices show up in the OFFLINE state when you query pool status. For information about querying pool status, see Querying ZFS Storage Pool Status.

For more information on device health, see Determining the Health Status of ZFS Storage Pools.