Profile level attributes

For a HSM systems to work properly, you should define and configure at least one of 16 different profiles HSM levels. Each level has its migration watermark setting for scheduled and emergency migration and WEIGHT ponders, which influence selection of objects to be pushed on lower HSM levels.

If for any reason any of the profiles defined on IMiS/ARChive need to be modified or updated, administrator can perform this action by selecting the profile that needs to be modified and edit its attributes. When profile is first selected, its in READ-ONLY mode by default. Administrator must first put profile in edit mode to modify its parameters (see Modifying an existing profile for more details).

Level
This box enables administrator to select which HSM level of the current profile needs to be changed. IMiS/ARChive supports up to 16 different HSM levels

Scheduled migration
When IMiS/ARChive object migrator initiates, it goes thru all profiles and their levels and calculates free space remaining on each level. Free space is defined as free space on all assigned volumes to this level to this profile. Volumes cannot be shared between levels and/or profiles. If used space on this level exceeds set watermark, the level is then cleaned to the set watermark. With this procedure the HSM levels remain viable and are ready to receive new objects.

Emergency migration
When for some reason (high frequency new objects, missed scheduled migration, etc.) level remains out of space (by that we mean all assigned volumes to this level are full) emergency migration is then initiated. For a HSM level to remain viable, it needs to have at least a small amount of space left. IMiS/ARChive object migrator then cleans the level to the set watermark which is usually (must be) higher then scheduled migration watermark). Emergency migration is initiated on the fly without user ever noticing it.

WEIGHT
When a level needs to be cleaned, IMiS/ARChive object migrator needs to filter out objects that will be pushed to a lower HSM level. You can influence this selection by modifying three parameters.

Frequency		How frequently is this object requested by users
Access		How many times users access this object
Creation		How old is an object

Based on these parameters IMiS/ARChive object migrator build a sorted list of objects which are then pushed until a set watermark is reached or level is fully emptied. By default a profile level weights are set to be dependent only on object creation which in basically means older object get pushed first.

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