This window allows you to manage a Purge Policy. Purge policies are assigned to storage classes to tell
the Migration Purge Server and Core Server how to free disk space occupied by files which have been
migrated. Purge policies apply to disk storage classes only.
The window always includes the Basic tab and may include one or more Subsystem tabs. These will be
referred to as "basic" and "subsystem" below.
Each purge policy consists of a single basic policy and zero or more subsystem policies. Each subsystem
policy has the same policy ID and name as its basic policy. When a new purge policy is needed, the basic
policy must be created first; subsystem policies can then be created as needed.
When HPSS needs to apply a purge policy to a subsystem, it first searches for a matching subsystem
policy. If none is found, HPSS uses the basic policy. You can consider the basic policy to be the default
for all subsystems which do not have policies of their own.
After changing any purge policy information, the changes will take effect for each Migration Purge
Server (MPS) when the MPS is restarted or when it rereads the changed policy. In addition, s ome
changes may require servers to be restarted.
When creating a subsystem policy, fields which differ from the basic policy values can be thought of as
exceptions to the basic policy values. However, this does not imply that unchanged defaults maintain any
links with the basic policy. Changes in the basic policy have no effect on subsystem policies.
Field Descriptions
Policy Name. The descriptive name of the Purge Policy.
Policy ID. A unique ID associated with the Purge Policy.
Do not purge files last accessed within. A file will not be a candida te for purge until it has remained
HPSS Management Guide November 2009
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