NONVIO

NONVIO={dsname                       }
       {(dsname1,dsname2,...,dsnameN)}

This parameter allows an installation to direct VIO paging away from the specified local page data sets. Specify one or more local page data sets that are not to be used for VIO paging when space is available on other local page data sets. The page data sets that are designated as non-VIO contain only address space pages or free slots. However, if space is depleted on the page data sets that allow VIO paging, the non-VIO page data sets are used for VIO paging. (Using non-VIO page data sets for VIO pages is called an overflow condition. The operator is notified if an overflow condition occurs.)

Each dsname that is specified must be a valid name consisting of a maximum of 44 characters whose format is the same as that required for the PAGE system parameter. Each dsname must specify a data set that was specified as a local page data set on the PAGE parameter, either in the IEASYSxx parmlib member or by the operator in response to the “SPECIFY SYSTEM PARAMETERS” prompt.

If you specify a name that the system cannot identify as the name of a local page data set, then the system ignores that name and issues a message to inform the operator that the data set cannot be recognized as a non-VIO page data set. If you omit the NONVIO parameter, then VIO pages are allowed on all local page data sets.

The name of the NONVIO data sets you specify can include the &SYSNAME system symbol. Using the same system symbol syntax with the NONVIO parameter that was used with the PAGE parameter can simplify your system maintenance.

For cold or quick starts a data set's NONVIO designation is not preserved; you must respecify the NONVIO system parameter. If you do not designate a data set as non-VIO on a cold or quick start, you can designate it in the NONVIO system parameter when you do a subsequent warm start; that data set is marked as non-VIO then, and no more VIO pages are sent to it (unless an overflow condition occurs). If the non-VIO paging data set remains on the system long enough, all VIO pages on it will eventually migrate, during the normal course of system operation, to other page data sets used for VIO.

For warm starts, a data set's NONVIO designation is preserved. A warm start preserves journaled VIO data set pages. Therefore, all local page data sets that contain VIO pages are required for a warm start. These required data sets would include non-VIO page data sets to which VIO paging was done because of an overflow condition.

Note: During a warm start, a quick start is forced if a local page data set, not specified as NONVIO, is unavailable or unusable, or a non-VIO local page data set that contains VIO pages was removed before all of its VIO pages had migrated to other page data sets used for VIO.

If you specify all local page data sets on the NONVIO data set name list, a message is issued to inform the operator of this condition. VIO pages can be written to all local page data sets. Similarly, if the directed VIO function is turned off via the DVIO parameter in the IEAOPTxx parmlib member, all local page data sets can receive VIO pages. If the directed VIO function is turned on again, then auxiliary storage management directs VIO away from any local page data sets designated as NONVIO. The VIO pages on these data sets will eventually migrate to VIO page data sets.

Value range: Any number of data set names can be specified up to the same limit as exists for the PAGE system parameter. The data set names can contain system symbols.

Default: None

Associated parmlib member: While there is no directly-associated parmlib member you must specify DVIO=YES in the IEAOPTxx parmlib member to activate the directed VIO function; DVIO=NO allows VIO pages to go to any local page data set.

Note: DVIO=YES is the default in the IEAOPTxx parmlib member allowing the use of the directed VIO.