Adding Devices to a Storage Pool
You can dynamically add disk space to a pool by adding a new top-level virtual device. This disk space is immediately available to all datasets in 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. 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 the zeepool pool's existing configuration.
For more information about how virtual device validation is done, see Detecting In-Use Devices.
Example 4–1 Adding Disks to a Mirrored ZFS Configuration
In the following example, another mirror is added to an existing mirrored ZFS configuration on Oracle's 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
|
Example 4–2 Adding Disks to a RAID-Z Configuration
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 that contains three disks to a storage pool with two RAID-Z devices that contains three disks each.
# 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
c2t2d0 ONLINE 0 0 0
c2t3d0 ONLINE 0 0 0
c2t4d0 ONLINE 0 0 0
errors: No known data errors
|
Example 4–3 Adding and Removing a Mirrored Log Device
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 Log 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
|
Example 4–4 Adding and Removing Cache Devices
You can add to your ZFS storage pool and remove them if they are no longer required..
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. Nonredundant 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.
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