File System configured incorrectly for ODM shuts down Oracle


File System configured incorrectly for ODM shuts down Oracle
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Linking Oracle RAC with the Veritas ODM libraries provides the best file system performance.

Review the instructions on creating the link and confirming that Oracle uses the libraries. Shared file systems in RAC clusters without ODM libraries linked to Oracle RAC may exhibit slow performance and are not supported.

If ODM cannot find the resources it needs to provide support for cluster file systems, it does not allow Oracle to identify cluster files and causes Oracle to fail at startup.

To verify cluster status, run the following command and review the output:

# cat /dev/odm/cluster

cluster status: enabled

If the status is "enabled," ODM is supporting cluster files. Any other cluster status indicates that ODM is not supporting cluster files. Other possible values include:

pending	ODM cannot yet communicate with its peers, but anticipates being able to eventually.
failed	ODM cluster support has failed to initialize properly. Check console logs.
disabled	ODM is not supporting cluster files. If you think ODM should be supporting the cluster files: Check /dev/odm mount options using mount. If the nocluster option is being used, it can force the disabled cluster support state. Make sure that the VRTSgms (group messaging service) fileset is installed. Run the following command: # `lslpp -l \| grep VRTSgms`

If /dev/odm is not mounted, no status can be reported.

The following procedure can be used to check and debug the ODM.

To verify and debug ODM

Verify that the io attribute in /dev/odm/stats is a non-zero value:

$ cat /dev/odm/stats | grep io

    
io:                    647   
io req:                618
io calls:              450
io mor cmp:              0
io zro cmp:              0
io nop cmp:             79

Note:

A non-zero number indicates that ODM is working.

To reset the ODM statistics, run the following command as the root user:
```
# odmstat -r /data/vcsdb/*
```
To reset the ODM statistics for a particular file:
```
# odmstat -r /file_path
```
For managing the ODM files, refer to the odmstat and odmmkfile VxFS man pages.