Considerations for using disks from a multi-disk carrier storage shelf in an aggregate

Observing the requirements and best practices for using disks from a multi-disk carrier disk shelf in an aggregate enables you to maximize storage redundancy and minimize the impact of disk failures.

Disks in multi-disk carriers always have the Data ONTAP disk type of MSATA. MSATA disks cannot be mixed with HDDs from a single-carrier disk shelf in the same aggregate.

The following disk layout requirements apply when you are creating or increasing the size of an aggregate composed of MSATA disks:

Data ONTAP prevents you from putting two disks in the same carrier into the same RAID group.
Do not put two disks in the same carrier into different pools, even if the shelf is supplying disks to both pools.
Do not assign disks in the same carrier to different nodes.
For the best layout, do not name specific disks; allow Data ONTAP to select the disks to be used or added.
If the operation cannot result in an optimal layout due to the placement of the disks and available spares, Data ONTAP automatically swaps disk contents until an optimal layout is achieved. If there are not enough available spares to support the swaps, Data ONTAP issues a warning and waits to perform the disk swaps until you provide the necessary number of hot spares. If you name disks and an optimal layout cannot be achieved, you must explicitly force the operation; otherwise, the operation fails.

Aggregate creation example

To create an aggregate using MSATA disks, you can specify the disk type and size but leave the disk selection and layout to Data ONTAP by using a command like this:

aggr create n1_aggr1 -T MSATA 14