Tuning Cached ODM settings for individual files in SFHA environment
You can use the odmadm setcachefile command to override the cachemap for a specific file so that ODM caches either all or none of the I/O to the file. The caching state can be ON, OFF, or DEF (default). The DEF caching state is conditional caching, meaning that for each I/O, ODM consults the cachemap and determines whether the specified file type and I/O type combination should be cached. The ON caching state causes the specified file always to be cached, while the OFF caching state causes the specified file never to be cached.
See the odmadm
(1M) manual page.
Note: |
The cache advisories operate only if Cached ODM is enabled for the file system. If the odm_cache_enable flag is zero, Cached ODM is OFF for all of the files in that file system, even if the individual file cache advisory for a file is ON. |
To enable unconditional caching on a file
- Enable unconditional caching on the file
/mnt1/file1
: # /opt/VRTS/bin/odmadm setcachefile /mnt1/file1=on
With this command, ODM caches all reads from file1
.
To disable caching on a file
- Disable caching on the file
/mnt1/file1
: # /opt/VRTS/bin/odmadm setcachefile /mnt1/file1=off
With this command, ODM does not cache reads from file1
.
To check on the current cache advisory settings for a file
To reset all files to the default cache advisory