How you can use effective ONTAP disk type for mixing HDDs

Starting with Data ONTAP 8.1, certain ONTAP disk types are considered equivalent for the purposes of creating and adding to aggregates, and managing spares. ONTAP assigns an effective disk type for each disk type. You can mix HDDs that have the same effective disk type.

When the raid.disktype.enable option is set to off, you can mix certain types of HDDs within the same aggregate. When the raid.disktype.enable option is set to on, the effective disk type is the same as the ONTAP disk type. Aggregates can be created using only one disk type. The default value for the raid.disktype.enable option is off.

Starting with Data ONTAP 8.2, the option raid.mix.hdd.disktype.capacity must be set to on to mix disks of type BSAS, FSAS, and ATA. The option raid.mix.hdd.disktype.performance must be set to on to mix disks of type FCAL and SAS.

The following table shows how the disk types map to the effective disk type:

ONTAP disk type Effective disk type
FCAL SAS
SAS SAS
ATA FSAS
BSAS FSAS
FCAL and SAS SAS
MSATA MSATA
FSAS FSAS