rootvg Disk replacement in AIX :

1. Connect new disk to system
2. Add new disk to volume group:
# extendvg vg_name hdiskY
3. Migrate old disk to new disk: (*)
# migratepv -l hd5 hdiskX hdiskY
# bosboot -ad /dev/hdiskY
# chpv -c /dev/hdiskX
# bootlist ...
#migratepv hdiskX hdiskY
4. Remove old disk from volume group:
# reducevg vg_name hdiskX
5. Remove old disk from ODM:
# rmdev -l hdiskX –d