Control disk cache size | Additional disk cache tuning parameters
Configure offload location
Direct the offload to disk location to a separate file system that has sufficiently large and preferably dedicated space.
If the disk offload location is not specified, the default location...
${WAS_TEMP_DIR}/node/servername/_dynacache/cacheJNDInameIf the disk offload location is specified, the node, server name, and cache instance name are appended. For example...
${USER_INSTALL_ROOT}/diskoffload...generates the location as....
${USER_INSTALL_ROOT}/diskoffload/node/servername/cacheJNDInameThis value is ignored if disk offload is not enabled.
The default value of ${WAS_TEMP_DIR} is...
${USER_INSTALL_ROOT}/tempIf you change the value of the ${WAS_TEMP_DIR} property after starting WebSphere Application Server, but do not move the disk cache contents to the new location:
- The application server creates a new disk cache file at the new disk offload location.
- If the Flush to disk setting is enabled, all of the disk cache content at the old location is lost when you restart the application server.
When you are specifying a directory, consider the following:
- If you expect to cache a large number of objects or large objects that will be around for some time, consider using a separate disk drive if you are using Windows operating systems, or a separate file system if you are using UNIX platforms.
- If you use the default directory and the disk fills up, WebSphere Application Server could possibly stall if it needs to write messages to log files and there is no more space.
- If you specify a directory such as /tmp on UNIX platforms and that directory fills up, you may have trouble logging onto the system.
- Depending on the operating system, you may see disk full messages on the console.
- When specifying a non-default location on a UNIX system, ensure that proper read/write permission is set on the directory so the WebSphere Application Server instance owner (for example, wasuser) can write to/read from the offload to disk directory.