Replacing disks that are currently being used in an aggregate

You can use the disk replace command to replace disks that are part of an aggregate without disrupting data service. You do this to swap out mismatched disks from a RAID group. Keeping your RAID groups homogenous helps optimize storage system performance.

Before You Begin

You should already have an appropriate hot spare disk of the correct type, size, speed and checksum type installed in your storage system. This spare must be assigned to the same system and pool as the disk it will replace.

Considerations

If you need to replace a disk—for example a mismatched data disk in a RAID group—you use the disk replace command. This command uses Rapid RAID Recovery to copy data from the specified old disk in a RAID group to the specified spare disk in the storage system. At the end of the process, the spare disk replaces the old disk as the new data disk, and the old disk becomes a spare disk in the storage system.

Note: If you replace a smaller disk with a larger disk, the capacity of the larger disk is downsized to match that of the smaller disk; the usable capacity of the aggregate is not increased.

Step

Enter the following command: disk replace start old_disk_name new_spare_name
If you need to use a disk that does not match the speed or pool of the other disks in the aggregate, you can use the -m option.

If you need to stop the disk replace operation, you can use the disk replace stop command. If you halt a disk replace operation, the target spare disk needs to be zeroed before it can be used as a data disk in another aggregate.

Parent topic: Managing disks

Related concepts

How Data ONTAP works with hot spares

How Data ONTAP works with disks

Software-based disk ownership guidelines

How disk ownership autoassignment works

Related tasks

Adding disks to a storage system

Assigning disk ownership