Releaser Concepts

This section describes concepts that are basic to the releaser process:

• Age

• Candidate

• Priority

• Weight

• Partial Release

Age

Age is the amount of time that elapsed from a given event to the present. A file's inode keeps track of the following times:

• Residence-change time

• Data-modified time

• Data-accessed time

You can view these times by using the sls command with the --D option. Each time has a corresponding age. For example, if it is 10:15 a.m., a file with a modify time of 10:10 a.m. has a data-modified age of five minutes. For more information, see sls(1) in Sun QFS and Sun Storage Archive Manager Reference Manual.

Candidate

A candidate is a file that is eligible to be released. A file is not a candidate under the following circumstances:

• The file is already offline.

• The file has not been archived.

• The archiver.cmd command file specifies the -norelease attribute for the file and the required copies have not yet been made.

• The file is marked as damaged.

• The file is not a directory, block, character-special file, or pipe.

• The archiver is staging the file to make an additional copy. The file becomes eligible for release after the archiver stages it.

• The age of the file is negative. This condition occurs for network file system (NFS) clients with inaccurate clock settings.

• The file is marked to never be released. You can use the release -n command to specify this.

• The file was staged at a time in the past that is less than the minimum residence time setting.

• The file was flagged for partial release, through the release command's --p option, and it is already partially released.

• The file is too small. Releasing it will not create much space.

Priority

A priority is a numeric value that indicates the rank of a candidate file based on user-supplied weights that are applied to numeric attributes of that candidate. The overall priority is the sum of two types of priority: age priority and size priority. Candidate files with numerically larger priorities are released before candidates with numerically smaller priorities.

Weight

A weight is a numeric value that biases the priority calculation to include file attributes in which you are interested and to exclude file attributes in which you are not interested. For example, if the size weight is set to 0, the size attribute of a file is excluded from the priority calculation. Weights are floating-point values from 0.0 to 1.0.

Partial Release

With partial release, a beginning portion of the file remains in disk cache while the rest of the file is released. Partial release is useful with utilities such as filemgr that read the beginning of a file.