ASM online disk migration from one disk array to another with zero downtime to database's and the dependent applications..sounds interesting...this was one of the tasks I was involved in recently for multiple Red Hat Linux clusters with ASM disk groups setup with "external" redundancy...
Actually this is a fairly straight forward activity if all the prerequisites are met and with some planning in place.
Here's the high-level work flow...
Multiple ASM Disk Groups with External redundancy
RHEL OS
multipath -v3 >&-
/dev/mapper/
create a simple shell script and execute the commands to avoid any typos as you'll have multiple disks to add, use a distinct to distinguish the new array disks from the current array.
The above query should return no rows...when the rebalance operation is complete...
Actually this is a fairly straight forward activity if all the prerequisites are met and with some planning in place.
Here's the high-level work flow...
Multiple ASM Disk Groups with External redundancy
RHEL OS
- List disks using /etc/init.d/oracleasm listdisks
- Identify the multipath device to ASM device mapping using
- Add the new LUN's at the OS level and ensure multipath has been setup for the new LUN's
- Create whole partitions on the new LUN's using fdisk or parted
- To discover the partitions, used below multipath commands..to flush and discover on all remaining nodes
multipath -v3 >&-
- create new ASK disks as below
create a simple shell script and execute the commands to avoid any typos as you'll have multiple disks to add, use a distinct
- Run /etc/init.d/oracleasm scandisks/listdisks on all the nodes to ensure the new ASM disks are identified
- Change the rebalance power limit of the disk group using ...
ALTER DISKGROUP DATA REBALANCE POWER 6; - Add the new ASM disks to the disk group using asmca as grid OS user
- Wait for the rebalance operation to complete..
SELECT * FROM GV$ASM_OPERATION;
The above query should return no rows...when the rebalance operation is complete...
- Once the rebalance is complete, drop the old set of disks using asmca as grid OS user
- Wait for the rebalance operation to complete..
SELECT * FROM GV$ASM_OPERATION;
The above query should return no rows...when the rebalance operation is complete...- Verify the status of disks using...
select disk_number,mount_status,header_status,mode_status,state,redundancy,failgroup,path
from v$asm_disk order by path;
- If the disks HEADER status is 'FORMER', proceed with deletedisk command as below...
/etc/init.d/oracleasm deletedisk ASM_DATA01
- Advise the sysadmin to tidy up the multipath configuration.
- Advise the storage admin to unpresent the LUN's from the host
