
user does not specify a COS or any hints with the creation request. The global  configuration specifies a 
default COS for an entire HPSS installation. Selecting a COS on the storage subsy stem configuration 
window allows the global value to be overridden for a particular subsystem.
If the field is blank, the global default COS will be used. If no Classes  of Service are configured, this 
value can be updated after the Classes of Service are in place.
Subsystem Name. The descriptive name of the storage subsystem. This field may be set only when the 
storage subsystem is created. The name should be unique and informative. It can contain a character  
string up to 31 bytes long. The default value is “Subsystem #<ID>”.
Database Name. The name of the database to be used to store the metadata for the st orage subsystem.
Gatekeeper.  The default value is “None”.
Advice - If an appropriate Gatekeeper has not yet been configured, simply le ave this configuration entry 
blank. It can be updated after the Gatekeeper is in place.
Allowed COS list. A list of Classes of Service that can be used by this subsystem. To  allow a COS to be 
used by this subsystem, the corresponding checkbox must be selected in the Allow column of the list. At 
least one COS must always be selected.  The user will not be permitted to de-select the  COS defined to 
be the Default Class of Service. If this subsystem configuration does not have a Default Class of  Service 
defined, then the COS chosen as the Global Configuration’s Default Class of Service  cannot be de-
selected.
Note that a newly created COS will not appear in the selection list unti l the Core Server and 
Migration Purge Server associated with the subsystem have been recycled. When new Class es of 
Service are added, the initial allowed state for that COS is determined  by the current setting for 
the other Classes of Service. If all previous Classes of Service were  allowed, the new COS will 
be allowed. Otherwise, the new COS will be disallowed.
Advice - By default, the servers in a subsystem are able to use any configured  COS. This table allows an 
administrator to prevent a subsystem from using particular Classes of Servi ce.
When a new Class of Service is added to a system, it will automatically be enabled  for all subsystems 
which have no disabled Classes of Service. It will be disabled in all other  subsystems. If this is not the 
desired configuration, the COS will have to be allowed/disallowed for each  subsystem individually.
Disallowing all Classes of Service in a subsystem is not permitted.
Metadata Space Warning Threshold. The Core Server in this subsystem will issue a warning alarm 
periodically and set its Opstate to Major when the percentage of used spac e in any DB2 tablespace in this 
subsystem’s database exceeds this value.
Metadata Space Critical Threshold. The Core Server in this subsystem will issue a criti cal alarm 
periodically and set its Opstate to Critical when the percentage of used spa ce in any DB2 tablespace in 
this subsystem’s database exceeds this value.
Metadata Space Monitor Interval. The Core Server for this subsystem will check the metadata  usage 
statistics at the indicated interval, specified in seconds.  If a value of  0 is specified, the Global 
Configuration setting will be used for this storage subsystem. The minimum value for this field i s 1800 
seconds (30 minutes).
HPSS Management Guide November 2009
Release 7.3 (Revision 1.0) 78