Reassigning disks to nodes
You can use System Manager to reassign the ownership of spare disks from one node to another node to increase the capacity of an aggregate or storage pool.
Viewing disk information
You can use the Disks window in System Manager to view the name, size, and container details of disks along with graphical information about capacity disks and cache disks.
Understanding RAID drive types
Data ONTAP classifies drives (or, for partitioned drives, partitions) as one of four types for RAID: data, hot spare, parity, or dParity. You manage disks differently depending on whether they are spare or being used in an aggregate.
How ONTAP reports disk types
ONTAP associates a type with every disk. ONTAP reports some disk types differently than the industry standards; you should understand how ONTAP disk types map to industry standards to avoid confusion.
How hot spare disks work
A hot spare disk is a disk that is assigned to a storage system and is ready for use, but is not in use by a RAID group and does not hold any data.
RAID protection for array LUNs
Storage arrays provide RAID protection for the array LUNs that they make available to Data ONTAP. Data ONTAP does not provide RAID protection.
Minimum number of hot spares you should have
Having insufficient spares increases the risk of a disk failure with no available spare, resulting in a degraded RAID group. A spare disk is also required to provide important information (a core file) to technical support in case of a controller disruption.
Spare requirements for multi-disk carrier disks
Maintaining the proper number of spares for disks in multi-disk carriers is critical for optimizing storage redundancy and minimizing the amount of time Data ONTAP must spend copying disks to achieve an optimal disk layout.
How to determine when it is safe to remove a multi-disk carrier
Removing a multi-disk carrier before it is safe to do so can result in one or more RAID groups becoming degraded, or possibly even a storage disruption. System Manager enables you to determine when it is safe to remove a multi-disk carrier.
Considerations for sizing RAID groups
Configuring an optimum RAID group size requires a trade-off of factors. You must decide which factors—speed of RAID rebuild, assurance against risk of data loss due to drive failure, optimizing I/O performance, and maximizing data storage space—are most important for the aggregate that you are configuring.
Considerations for ONTAP RAID groups for array LUNs
Setting up ONTAP RAID groups for array LUNs requires planning and coordination with the storage array administrator so that the administrator makes the number and size of array LUNs that you need available to ONTAP.
Disks window
You can use the Disks window to view all the disks in your storage system.