NetApp
Cluster-Mode System Manager Help : Cluster-Mode : Cluster > Storage > Aggregates : Managing aggregates : Adding disks to an aggregate
Adding disks to an aggregate
You can add hot spare disks to an aggregate to replace disks or to increase its size so that it can provide more storage space to its contained volumes. You can use the Add Disks to Aggregate dialog box to add hot spare disks to an existing aggregate.
Before you begin 
An appropriate number of hot spare disks must be available.
About this task 
You cannot add disks to a mirrored aggregate if one of the plexes is offline.
Steps 
1.
From the Home tab, double-click the appropriate storage system.
2.
In the navigation pane, click Storage > Aggregates.
3.
Select an aggregate to which you want to add disks and click Add Disks.
4.
Select one or more spare disks and click Add.
5.
Verify that the disks are added to the aggregate.