In a 2-node FAS8700 ONTAP 9.8 cluster with 24x16 TB NL-SAS disks, an aggregate was created with one RAID group and two spare disks. How many data drives are in the aggregate?

In a 2-node FAS8700 ONTAP 9.8 cluster with 24x16 TB NL-SAS disks, an aggregate was created with one RAID group and two spare disks. How many data drives are in the aggregate?

• A. 17
• B. 19
• C. 21
• D. 23

Answer: (B)

In ONTAP, an aggregate is built from RAID groups, and only the disks that actually store user data are counted as data drives. Spares are reserved to replace failed drives and do not contribute to data capacity. For RAID-DP (double parity), two disks in the RAID group serve as parity. Here, you have 24 disks total with two configured as hot spares. That leaves 22 disks in the RAID group. Of those 22, two are parity disks, so the number of data disks is 22 − 2 = 20. So, the aggregate would have 20 data drives. The prompt’s stated answer (19) would imply an additional disk reserved for something not described (such as an extra system/root disk), which isn’t part of the standard calculation.

In ONTAP, an aggregate is built from RAID groups, and only the disks that actually store user data are counted as data drives. Spares are reserved to replace failed drives and do not contribute to data capacity. For RAID-DP (double parity), two disks in the RAID group serve as parity.

Here, you have 24 disks total with two configured as hot spares. That leaves 22 disks in the RAID group. Of those 22, two are parity disks, so the number of data disks is 22 − 2 = 20.

So, the aggregate would have 20 data drives. The prompt’s stated answer (19) would imply an additional disk reserved for something not described (such as an extra system/root disk), which isn’t part of the standard calculation.