Veritas Storage Foundation 5.1 SP1: Storage and Availability Management for Oracle (5900-1504, April 2011)

Enabling Cached ODM for file systems

Cached ODM is initially disabled on a file system. You can enable Cached ODM

for a file system by setting the odm_cache_enable option of the vxtunefs command

after the file system is mounted.

See the vxtunefs(1M) manual page.

Note: The vxtunefs command enables conditional caching for all of the ODM files

on the file system.

To enable Cached ODM for a file system

Enable Cached ODM on the VxFS file system /database01:

# vxtunefs -o odm_cache_enable=1 /database01

Optionally, you can make this setting persistent across mounts by adding a

file system entry in the file /etc/vx/tunefstab:

/dev/vx/dsk/datadg/database01 odm_cache_enable=1

See the tunefstab(4) manual page.

For Cluster File System, you must modify /etc/vx/tunefstab on all nodes.

Tuning Cached ODM settings for individual files

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.

Improving database performance with Veritas Cached Oracle Disk Manager

Configuring Cached ODM