You can dynamically add space to a pool by adding a new top-level virtual device. This space is immediately available to all datasets within the pool. To add a new virtual device to a pool, use the zpool add command. For example:
# zpool add zeepool mirror c2t1d0 c2t2d0 |
The format for specifying the virtual devices is the same as for the zpool create command, and the same rules apply. Devices are checked to determine if they are in use, and the command cannot change the level of redundancy without the -f option. The command also supports the -n option so that you can perform a dry run. For example:
# zpool add -n zeepool mirror c3t1d0 c3t2d0 would update 'zeepool' to the following configuration: zeepool mirror c1t0d0 c1t1d0 mirror c2t1d0 c2t2d0 mirror c3t1d0 c3t2d0 |
This command syntax would add mirrored devices c3t1d0 and c3t2d0 to zeepool's existing configuration.
For more information about how virtual device validation is done, see Detecting In-Use Devices.
In the following example, another mirror is added to an existing mirrored ZFS configuration on a Sun Fire x4500 system.
# zpool status tank pool: tank state: ONLINE scrub: none requested config: NAME STATE READ WRITE CKSUM tank ONLINE 0 0 0 mirror-0 ONLINE 0 0 0 c0t1d0 ONLINE 0 0 0 c1t1d0 ONLINE 0 0 0 mirror-1 ONLINE 0 0 0 c0t2d0 ONLINE 0 0 0 c1t2d0 ONLINE 0 0 0 errors: No known data errors # zpool add tank mirror c0t3d0 c1t3d0 # zpool status tank pool: tank state: ONLINE scrub: none requested config: NAME STATE READ WRITE CKSUM tank ONLINE 0 0 0 mirror-0 ONLINE 0 0 0 c0t1d0 ONLINE 0 0 0 c1t1d0 ONLINE 0 0 0 mirror-1 ONLINE 0 0 0 c0t2d0 ONLINE 0 0 0 c1t2d0 ONLINE 0 0 0 mirror-2 ONLINE 0 0 0 c0t3d0 ONLINE 0 0 0 c1t3d0 ONLINE 0 0 0 errors: No known data errors |
Additional disks can be added similarly to a RAID-Z configuration. The following example shows how to convert a storage pool with one RAID–Z device comprised of 3 disks to a storage pool with two RAID-Z devices comprised of 3 disks.
# zpool status rzpool pool: rzpool state: ONLINE scrub: none requested config: NAME STATE READ WRITE CKSUM rzpool ONLINE 0 0 0 raidz1-0 ONLINE 0 0 0 c1t2d0 ONLINE 0 0 0 c1t3d0 ONLINE 0 0 0 c1t4d0 ONLINE 0 0 0 errors: No known data errors # zpool add rzpool raidz c2t2d0 c2t3d0 c2t4d0 # zpool status rzpool pool: rzpool state: ONLINE scrub: none requested config: NAME STATE READ WRITE CKSUM rzpool ONLINE 0 0 0 raidz1-0 ONLINE 0 0 0 c1t0d0 ONLINE 0 0 0 c1t2d0 ONLINE 0 0 0 c1t3d0 ONLINE 0 0 0 raidz1-1 ONLINE 0 0 0 c1t4d0 ONLINE 0 0 0 c1t5d0 ONLINE 0 0 0 c1t6d0 ONLINE 0 0 0 errors: No known data errors |
The following example shows how to add a mirrored log device to mirrored storage pool.For more information about using log devices in your storage pool, see Setting Up Separate ZFS Logging Devices.
# zpool status newpool pool: newpool state: ONLINE scrub: none requested config: NAME STATE READ WRITE CKSUM newpool ONLINE 0 0 0 mirror-0 ONLINE 0 0 0 c0t4d0 ONLINE 0 0 0 c0t5d0 ONLINE 0 0 0 errors: No known data errors # zpool add newpool log mirror c0t6d0 c0t7d0 # zpool status newpool pool: newpool state: ONLINE scrub: none requested config: NAME STATE READ WRITE CKSUM newpool ONLINE 0 0 0 mirror-0 ONLINE 0 0 0 c0t4d0 ONLINE 0 0 0 c0t5d0 ONLINE 0 0 0 logs mirror-1 ONLINE 0 0 0 c0t6d0 ONLINE 0 0 0 c0t7d0 ONLINE 0 0 0 errors: No known data errors |
You can attach a log device to an existing log device to create a mirrored log device. This operation is identical to attaching a device in a unmirrored storage pool.
Log devices can be removed by using the zpool remove command. The mirrored log device in the previous example can be removed by specifying the mirror-1 argument. For example:
# zpool remove newpool mirror-1 # zpool status newpool pool: newpool state: ONLINE scrub: none requested config: NAME STATE READ WRITE CKSUM newpool ONLINE 0 0 0 mirror-0 ONLINE 0 0 0 c0t4d0 ONLINE 0 0 0 c0t5d0 ONLINE 0 0 0 errors: No known data errors |
If your pool configuration only contains one log device, you would remove the log device by specifying the device name. For example:
# zpool status pool pool: pool state: ONLINE scrub: none requested config: NAME STATE READ WRITE CKSUM pool ONLINE 0 0 0 raidz1-0 ONLINE 0 0 0 c0t8d0 ONLINE 0 0 0 c0t9d0 ONLINE 0 0 0 logs c0t10d0 ONLINE 0 0 0 errors: No known data errors # zpool remove pool c0t10d0 |
You can add and remove cache devices to your ZFS storage pool.
Use the zpool add command to add cache devices. For example:
# zpool add tank cache c2t5d0 c2t8d0 # zpool status tank pool: tank state: ONLINE scrub: none requested config: NAME STATE READ WRITE CKSUM tank ONLINE 0 0 0 mirror-0 ONLINE 0 0 0 c2t0d0 ONLINE 0 0 0 c2t1d0 ONLINE 0 0 0 c2t3d0 ONLINE 0 0 0 cache c2t5d0 ONLINE 0 0 0 c2t8d0 ONLINE 0 0 0 errors: No known data errors |
Cache devices cannot be mirrored or be part of a RAID-Z configuration.
Use the zpool remove command to remove cache devices. For example:
# zpool remove tank c2t5d0 c2t8d0 # zpool status tank pool: tank state: ONLINE scrub: none requested config: NAME STATE READ WRITE CKSUM tank ONLINE 0 0 0 mirror-0 ONLINE 0 0 0 c2t0d0 ONLINE 0 0 0 c2t1d0 ONLINE 0 0 0 c2t3d0 ONLINE 0 0 0 errors: No known data errors |
Currently, the zpool remove command only supports removing hot spares, log devices, and cache devices. Devices that are part of the main mirrored pool configuration can be removed by using the zpool detach command. Non-redundant and RAID-Z devices cannot be removed from a pool.
For more information about using cache devices in a ZFS storage pool, see Creating a ZFS Storage Pool with Cache Devices.