How you can use effective Data ONTAP disk type for mixing HDDs

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

Data ONTAP disk type	Effective disk type
FCAL	SAS
SAS	SAS
ATA	SATA
SATA	SATA
BSAS	SATA
FCAL and SAS	SAS
ATA and SATA	SATA
ATA, SATA, and BSAS	SATA