Rename ASM disk group in Oracle 12c RAC Database

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In this article I am illustrating how to rename ASM Disk group in oracle 12c.

The tool renamedg facilitates to rename the ASM disk group(s) in oracle.  There are two options available in renamedg tool to rename diskgroup(s).

  1. Specify “BOTH” argument in the PHASE parameter of renamedg tool.
  2. Specify “one and two” arguments in the PHASE parameter of renamedg tool.

  How to rename the ASM disk group using “BOTH” argument.

  • Take the backup of the database (optional, but for the safer side).
  • Bring down the database. (If your disk groups are actively used by any Database processes)
  • Log in to ASM Instance and :-
    • Get disk group(s) and its associated disk(s) details.
    • Dismount the disk group(s) from all the nodes.
      (You cannot use renamedg tools to rename CRS disk group because: (1) You cannot dismount the disk group , as it’s being used by Cluster actively. (2) You cannot rename the disk group(s) or disk(s) when CRS is down.)
  • Use renamedg utility to rename the disk group. This is a command line utility.
  • After renaming the disk groups, you can rename the disks in disk group that assign to the disk group. Before rename the disks in disk group, you need to mount the disk group in restricted mode.
  • Once rename activities completed, Mount the entire disk group manually that was renamed.
  • The original disk group resource is not automatically deleted. The status of the old disk group resource can be checked with the Oracle Clusterware Control (CRSCTL) crsctl stat res -t command and then manually deleted with the Server Control Utility (SRVCTL) srvctl remove disk group command. . If those disk group are associated with Database, you need to remove database resource and add it again.

Quick Commands:

  • Get Disk Details

select dg.name “DG Name” ,di.name “Disk Name”,di.path

from v$asm_diskgroup dg, v$asm_disk di

where dg.GROUP_NUMBER=di.GROUP_NUMBER

order by 1;

DG Name Disk Name PATH
PRAD_CTL1 PRAD_CTL1_0000 /dev/rhdiskpower10
PRAD_CTL2 PRAD_CTL2_0000 /dev/rhdiskpower11
PRAD_CTL3 PRAD_CTL3_0000 /dev/rhdiskpower12
PRAD_REDOA1 PRAD_REDOA1_0000 /dev/rhdiskpower6
PRAD_REDOA2 PRAD_REDOA2_0000 /dev/rhdiskpower7
PRAD_REDOB1 PRAD_REDOB1_0000 /dev/rhdiskpower8
PRAD_REDOB2 PRAD_REDOB2_0000 /dev/rhdiskpower9
PRAD_ROOT PRAD_ROOT_0000 /dev/rhdiskpower2
PRAD_SEED PRAD_SEED_0000 /dev/rhdiskpower5
PPRADTRN_DATA1 PPRADTRN_DATA1_0000 /dev/rhdiskpower3
PPRADTRN_INDX1 PPRADTRN_INDX1_0000 /dev/rhdiskpower4
  • Dismount Diskgroup

            alter diskgroup <DG Name> dismount;

  • Rename Diskgroup

Syntax:    renamedg [phase={one|two |both}] dgname=diskgroup

       newdgname=newdiskgroup [config=configfile]

     [asm_diskstring=discoverystring, discoverystring …]

     [clean={true|false}] [check={true|false}]

     [confirm={true|false}] [verbose={ true|false}]

     [keep_voting_files={true|false}]

Example: $ renamedg dgname=PRAD_ROOT newdgname=PRAD1_ROOT asm_diskstring=’/dev/emcpowerp1′ verbose=true

  • Mount Diskgroup Restricted

alter diskgroup <DG Name> mount restricted;

  • Rename Disk name

alter diskgroup <DG Name> rename disks all;

  • Mount Diskgroup

alter diskgroup <DG Name> mount;

How to rename the ASM disk group using “one and two” argument ( Only Commands).

Steps are all same as to rename the disk group(s) with “both” argument, except the usage of  renamedg.

  • Below command generates the configuration file to be used in phase two.

$renamedg phase=one dgname=<Current DG Name>  newdgname=<New DG name>      asm_diskstring=’/devices/disk*’ config=/tmp/disks.conf verbose=true

  • Rename the disk group using configuration file.

$ renamedg phase=two dgname=<Current DG Name> newdgname=<New DG Name> config=/tmp/disks.conf   verbose=true

  • Mount Diskgroup Restricted

alter diskgroup <DG Name> mount restricted;

  • Rename Disk name

alter diskgroup <DG Name> rename disks all;

                                                ***

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