NetApp
Cluster-Mode System Manager Help : Cluster-Mode : Cluster > Storage > Aggregates : Understanding aggregates : How Data ONTAP RAID groups work
How Data ONTAP RAID groups work
A RAID group consists of one or more data disks or array LUNs, across which client data is striped and stored, and up to two parity disks, depending on the RAID level of the aggregate that contains the RAID group.
RAID-DP uses two parity disks to ensure data recoverability even if two disks within the RAID group fail.
RAID4 uses one parity disk to ensure data recoverability if one disk within the RAID group fails.
RAID0 does not use any parity disks; it does not provide data recoverability if any disks within the RAID group fail.
For native storage, Data ONTAP uses RAID-DP or RAID4 groups to provide parity protection. For third-party storage, Data ONTAP uses RAID0 groups to optimize performance and storage utilization. The storage arrays provide the parity protection for third-party storage.