000027928 - Determining how much space is used in the Oracle Automatic Storage Management (ASM) partition on an RSA Identity Governance & Lifecycle hardware appliance

RSA Product Set: Identity Governance & Lifecycle
RSA Version/Condition: 6.x, 7.x
Platform: Hardware Appliance

The Oracle Automatic Storage Management (Oracle ASM) partition, when used on an RSA Identity Governance & Lifecycle Hardware Appliance, is formatted and managed by the Oracle ASM software. As such, it is not seen by typical operating system space usage commands, such as df -kh, du -a, or ls -ltr.

The only way to see the ASM partition itself using an operating system command, is through a device command such as fdisk -l, run as the Linux root user.  However, the fdisk command only shows you the size of the partition, not how much space is used within that partition.

This article explains how to use the Oracle ASMCMD command line utility to determine how much space is available and how much space is in use on the ASM partition on Oracle versions 11g and 12g.
 

To see the ASM partition space used on an RSA Identity Governance & Lifecycle hardware appliance, both the ORACLE_SID and ORACLE_HOME environment variables must be re-defined to point to the +ASM instance instead of the AVDB instance.The ORACLE_SID environment variable needs to be set to +ASM, and the ORACLE_HOME environment variable must be set to point to the ORACLE_GRID_HOME. This can be done using the Linux export command.

Once the appropriate environment variables are defined, the Oracle ASM command asmcmd lsdg, can be used to see the actual ASM space used. This command can be run as either the Linux admin or oracle user.
 

NOTE: In the example below, only part of the information returned by this command is shown.

1. Set the environment variables:

$ echo $ORACLE_SID
AVDB

$ echo $ORACLE_GRID_HOME
/u01/app/11.2.0/grid

$ echo $ORACLE_HOME
/u01/app/oracle/product/11.2.0/db_1

$ export ORACLE_SID=+ASM
$ export ORACLE_HOME=$ORACLE_GRID_HOME
$ export PATH=$ORACLE_GRID_HOME/bin:$PATH

2. Run the ASMCMD to see disk space:

$ asmcmd lsdg

State    Type  Sector    Block      Total_MB    Free_MB       Name
 MNTD     EXT     512     4096                 307094            298612       DG01/

This output says there is approximately 300 GB of space available on the ASM partition, and approximately 290 GB of that space is currently being used.

3. Note that if the lsdg command returns:

[oracle@vm-support-04 ~]$ asmcmd
Connected to an idle instance.
ASMCMD> lsdg
ASMCMD-08102: no connection to ASM; command requires ASM to run

This could be an indication that there is very little or no space left on the local operating system partition, and is not indicative of space availability on ASM. When the local space is cleaned up, the lsdg command can return expected output.

4. After checking the ASM space, these environment variables should be redefined back to their defaults: ORACLE_HOME and ORACLE_SID.

$ export ORACLE_SID=AVDB
$ export ORACLE_HOME=/u01/app/oracle/product/11.2.0/db_1

The reason that both the ORACLE_SID and ORACLE_HOME environment variables need to be reset is to ensure that non-Grid commands function properly. Another way to do this would be to logoff, and login again, or by executing the RSA Identity Governance & Lifecycle script /home/oracle/setDeployEnv.sh.

If these environment variables are NOT redefined/reset, then execution of SQL*Plus to access the database might fail with an error like this:

$ sqlplus avuser/<avuser-password>

SQL*Plus: Release 11.2.0.2.0 Production on Mon Dec 5 17:46:51 2011

Copyright (c) 1982, 2010, Oracle. All rights reserved.

ERROR:
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
Linux-x86_64 Error: 2: No such file or directory
Process ID: 0
Session ID: 0 Serial number: 0