If you have disks of both checksum types (blocks and zoned) in your storage system, you must follow the checksum type rules when you add disks to an aggregate.
Data ONTAP enforces the following rules when creating aggregates or adding disks to existing aggregates:
- An aggregate can have only one checksum type, and it applies to the entire aggregate.
- To use block checksum disks (BCDs) when you create a new aggregate, you must have at least the number of block checksum spare disks available that you specified in the aggr create command.
- When you add disks to an existing aggregate, the following rules apply:
- You can add a BCD to either a block checksum aggregate or a zoned checksum aggregate.
- You cannot add a zoned checksum disk (ZCD) to a block checksum aggregate.
The following table shows the types of disks that you can add to an existing aggregate of each type.
| Disk checksum type |
Block checksum aggregate |
Zoned checksum aggregate |
|---|
| Block checksum |
OK |
OK |
| Zoned checksum |
Not allowed |
OK |
