Storage > Aggregates : Understanding aggregates : Understanding RAID disk types
Understanding RAID disk types
Data ONTAP classifies disks as one of four types for RAID: data, hot spare, parity, or dParity. The RAID disk type is determined by how RAID is using a disk.
Data disk
Holds data stored on behalf of clients within RAID groups (and any data generated about the state of the storage system as a result of a malfunction).
Spare disk
Does not hold usable data, but is available to be added to a RAID group in an aggregate. Any functioning disk that is not assigned to an aggregate but is assigned to a system functions as a hot spare disk.
Parity disk
Stores data reconstruction information within RAID groups.
dParity disk
Stores double-parity information within RAID groups, if RAID-DP is enabled.
