We have EMC CLARiiON disks that are near their end of support, so we need to move Oracle ASM disks to a new sets disks. We are trying to minimize the database down time, so I am trying to find ways to use ASM mirroring or disk clone method to move current databases on ASM old disks to new ones.

If our databases were on the file system, we could use the disk mirror/clone to copy the data files on the file system to new disks. We could then open the database on new disks with ease. But Oracle ASM disks are different than file systems.

Any suggestions or references will be very much appreciated.

1 Answer 1


Why not just create luns on the new storage, with same size as on old storage and add them to the existing disk groups. Next drop the old disks from the disk group and when the re-balance is over, your system is migrated to the new storage, without any downtime.

Works like a charm. ASM is way smarter than a filesystem.

  • Sure, I am quite confident this will help you. It is like cloning on block level.
    – user953
    Commented Oct 6, 2013 at 17:01
  • It worked perfectly. After rebalancing, you need to reboot server to pull out old disks.
    – dave
    Commented Nov 23, 2013 at 21:20
  • why? There have been bugs in Oracle that kept the disks busy/locked for the OS, despite being dropped. Check that. rebooting should now a days not be needed for just add/remove disks
    – user953
    Commented Nov 24, 2013 at 10:22
  • I read metalink that it is a bug that old disks are locked by OS after disks are dropped. I can actually restart db to release the locks. I have not tried to restart ASM to release its locks yet, but restart server works like a charm. My Unix admin told me he needs to restart server to pull the old disks out.
    – dave
    Commented Nov 25, 2013 at 15:47
  • yes, restarting the db releases the locks, no problem. There is a patch for that in case you are in a high available environments where downtime is no option.
    – user953
    Commented Nov 25, 2013 at 16:43

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