Chapter 1 HPSS BasicsHPSS Installation Guide September 2002 35Release 4.5, Revision 21.3.6 HPSS Management InterfaceHPSS provides a powerful SSM administration and operations GUI through the use of the Sammiproduct from Kinesix Corporation. Detailed information about Sammi can be found in the SammiRuntime Reference, Sammi User’s Guide, and Sammi System Administrator’s Guide.SSM simplifies the management of HPSS by organizing a broad range of technical data into a seriesof easy-to-read graphic displays. SSM allows monitoring and control of virtually all HPSSprocesses and resources from windows that can easily be added, deleted, moved, or overlapped asdesired.HPSS also provides a command line SSM interface, hpssadm. This tool does not provide all thefunctionality of the GUI, but does implement a subset of its frequently used features, such as somemonitoring and some control of servers, devices, storage classes, volumes, and alarms. It is usefulfor performing HPSS administration from remote locations where X traffic is slow, difficult, orimpossible, such as from home or from scripts. Additionally, hpssadm provides some rudimentarymass configuration support by means of the ability to issue configuration commands from a batchscript.1.3.7 HPSS Policy ModulesThere are a number of aspects of storage management that probably will differ at each HPSS site.For instance, sites typically have their own guidelines or policies covering the implementation ofaccounting, security, and other storage management operations. In order to accommodate site-specific policies, HPSS has implemented flexible interfaces to its servers to allow local sites thefreedom to tailor management operations to meet their particular needs.HPSS policies are implemented using two different approaches. Under the first approach—used formigration, purge, and logging policies—sites are provided with a large number of parameters thatmay be used to implement local policy. Under the second approach, HPSS communicatesinformation through a well-defined interface to a policy software module that can be completelyreplaced by a site. Under both approaches, HPSS provides a default policy set for users.• Migration Policy. The migration policy defines the conditions under which data is copiedfrom one level in a storage hierarchy to one or more lower levels. Each storage class that isto have data copied from that storage class to a lower level in the hierarchy has a migrationpolicy associated with it. The MPS uses this policy to control when files are copied and howmuch data is copied from the storage class in a given migration run. Migration runs arestarted automatically by the MPS based upon parameters in the migration policy.Note that the number of copies which migration makes and the location of these copies isdetermined by the definition of the storage hierarchy and not by the migration policy.• Purge Policy. The purge policy defines the conditions under which data that has alreadybeen migrated from a disk storage class can be deleted. Purge applies only to disk storageclasses. Each disk storage class which has a migration policy should also have a purgepolicy. Purge runs are started automatically by the MPS based upon parameters in thepurge policy.
