Level	Criteria for shelf/drawer loss protection	Minimum number of shelves/ drawers required
Pool	For shelves, the pool must contain no more than two drives in a single shelf. For drawers, the pool must include an equal number of drives from each drawer.	6 for shelves 5 for drawers
RAID 6	The volume group contains no more than two drives in a single shelf or drawer.	3
RAID 3 or RAID 5	Each drive in the volume group is located in a separate shelf or drawer.	3
RAID 1	Each drive in a mirrored pair must be located in a separate shelf or drawer.	2
RAID 0	Cannot achieve shelf/drawer loss protection.	Not applicable

Level

Criteria for shelf/drawer loss protection

Minimum number of shelves/ drawers required

Pool

For shelves, the pool must contain no more than two drives in a single shelf.
For drawers, the pool must include an equal number of drives from each drawer.

6 for shelves
5 for drawers

RAID 6

The volume group contains no more than two drives in a single shelf or drawer.

RAID 3 or RAID 5

Each drive in the volume group is located in a separate shelf or drawer.

RAID 1

Each drive in a mirrored pair must be located in a separate shelf or drawer.

RAID 0

Cannot achieve shelf/drawer loss protection.

Not applicable

Shelf/drawer loss protection is not maintained if a drive has already failed in the pool or volume group. In this situation, losing access to a drive shelf or drawer, and consequently another drive in the pool or volume group, causes loss of data.