When performing maintenance on storage servers, it might be necessary to power down or reboot the cell. If a storage server is to be shut down when one or more databases are running, then verify that taking a storage server offline does not impact Oracle ASM disk group and database availability. The ability to take a storage server offline without affecting database availability depends on two items:
Level of Oracle ASM redundancy used on the affected disk groups
Current status of disks in other storage servers that have mirror copies of data on the storage server to be taken offline
CellCLI> LIST GRIDDISK ATTRIBUTES name WHERE asmdeactivationoutcome != 'Yes'
If any grid disks are returned, then it is not safe to take a storage server offline, because proper Oracle ASM disk group redundancy will not be maintained. Taking a storage server offline when one or more grid disks are in this state causes Oracle ASM to dismount the affected disk group, causing the databases to shut down abruptly.
CellCLI> ALTER GRIDDISK ALL INACTIVE
The preceding command completes once all disks are inactive and offline.
LIST GRIDDISK WHERE STATUS != 'inactive'
If all grid disks are inactive, then you can shut down the storage server without affecting database availability.
The cell services start automatically.
CellCLI> ALTER GRIDDISK ALL ACTIVE
When the grid disks become active, Oracle ASM automatically synchronizes the grid disks to bring them back into the disk group.
CellCLI> LIST GRIDDISK ATTRIBUTES name, asmmodestatus
Wait until asmmodestatus is ONLINE or UNUSED for all grid disks. For example:
DATA_CD_00_dm01cel01 ONLINE DATA_CD_01_dm01cel01 SYNCING DATA_CD_02_dm01cel01 OFFLINE DATA_CD_02_dm02cel01 OFFLINE DATA_CD_02_dm03cel01 OFFLINE DATA_CD_02_dm04cel01 OFFLINE DATA_CD_02_dm05cel01 OFFLINE DATA_CD_02_dm06cel01 OFFLINE DATA_CD_02_dm07cel01 OFFLINE DATA_CD_02_dm08cel01 OFFLINE DATA_CD_02_dm09cel01 OFFLINE DATA_CD_02_dm10cel01 OFFLINE DATA_CD_02_dm11cel01 OFFLINE
Oracle ASM synchronization is complete only when all grid disks show asmmodestatus=ONLINE or asmmodestatus=UNUSED. Before taking another storage server offline, Oracle ASM synchronization must complete on the restarted storage server. If synchronization is not complete, the check performed on another storage server fails. For example:
CellCLI> list griddisk attributes name where asmdeactivationoutcome != 'Yes' DATA_CD_00_dm01cel02 "Cannot de-activate due to other offline disks in the diskgroup" DATA_CD_01_dm01cel02 "Cannot de-activate due to other offline disks in the diskgroup" DATA_CD_02_dm01cel02 "Cannot de-activate due to other offline disks in the diskgroup" DATA_CD_03_dm01cel02 "Cannot de-activate due to other offline disks in the diskgroup" DATA_CD_04_dm01cel02 "Cannot de-activate due to other offline disks in the diskgroup" DATA_CD_05_dm01cel02 "Cannot de-activate due to other offline disks in the diskgroup" DATA_CD_06_dm01cel02 "Cannot de-activate due to other offline disks in the diskgroup" DATA_CD_07_dm01cel02 "Cannot de-activate due to other offline disks in the diskgroup" DATA_CD_08_dm01cel02 "Cannot de-activate due to other offline disks in the diskgroup" DATA_CD_09_dm01cel02 "Cannot de-activate due to other offline disks in the diskgroup" DATA_CD_10_dm01cel02 "Cannot de-activate due to other offline disks in the diskgroup" DATA_CD_11_dm01cel02 "Cannot de-activate due to other offline disks in the diskgroup"