- Disk downsizing
- RAID groups
- NetApp Write Anyware File Layout (WAFL) uses Virtual Block numbers (VBNs) when creating RAID groups and aggregates.
- The VBNs used by each disk are "fixed" in the RAID group so, if a disk is replaced with a bigger one, the amount of VBNs will remain.
- The empty space in the bigger drive won't be used by WAFL for new VBNs. No data will be stored in the "available" space.
- The aggregate with mixed drives should be destroyed and recreated again with the correct ones.