Information about How to Remove ASM Diskgroups and ASM Instance
This document will describe how to remove an ASM instance from a RAC node. It will also describe the entire process for removing ASM, removing ASM Diskgroups, and reinstalling ASM Instance.
This process is used to clean up a failed ASM install and wipe all ASM Instance/Diskgroups to prepare systems for a new ASM installation.
Document CreatorTodd Walters
How to Remove ASM Instance and DiskGroups
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Check ASM status on RAC Nodes
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Login via oracle and run showcrs to view status.
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Stop ASM instance on each node:
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srvctl stop asm -n node (where node is node name, ie srv0dbxd11)
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Login to node 2 and 3 and run . oraenv and source +ASMx where X=instance number, ie. +ASM2 for node2.
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Go to sqlplus with sqlplus sys as sysdba and do the following on node 2 & 3 first:
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SQL> Alter diskgroup all dismount;
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Back on Node1, run sqlplus again and list all ASM Diskgroups with this command:
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SQL> select name,total_mb from v$asm_diskgroup;
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NAME TOTAL_MB
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DWAK_BACKUP_01 40954
DWAK_DATA_01 225252
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To remove these ASM Diskgroups, complete the following command (Make sure you want to remove these)
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SQL> drop diskgroup dwak_data_01 including contents;
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Should see: Dropped dwakdb_data_01 successfully
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Run drop command again for any other ASM diskgroups to remove.
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Next while logged in as Oracle on Node 1, remove all ASM instances
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srvctl remove asm -n nodeX (where nodeX=srv0dbxd13 for example)
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run for each node in RAC cluster.
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Next edit the /etc/oratab file on all nodes in RAC Cluster and remove the following line:
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+ASM1:/u00/app/oracle/product/10.2.0/ASM:N (remove this on all nodes)
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As root, verify all Oracle ASM disks are listed properly and run scandisks
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[[email protected] init.d]# ./oracleasm scandisks
Scanning system for ASM disks: [ OK ] -
then run ./oracleasm restart to restart ASM
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Once everything is okay, you can reinstall ASM Instance.
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Login to node 1 with VNC.
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Run xhost +
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su – oracle
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. oraenv
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+ASM1 and enter /u00/app/oracle/product/10.2.0/ASM for ORACLE_HOME
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cd $ORACLE_HOME/bin and run ./dbca
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choose Install ASM
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