Attributes of the object backup storage group

To define an object backup storage group you must specify the following attributes:

Description

This is an optional value of up to 120 characters that describes the object backup storage group.

Cycle Start Time

This identifies the beginning of a window of time. Use this field in association with Cycle End Time to specify a specific window of time in which object processing can be started for this object backup storage group.

Specify a value from 0 - 23, or NONE. A value from 0 - 23 represents an hour of the day. For example, specify 00 for midnight; 01 for 1 a.m.; or 23 for 11 p.m. Specify NONE if you do not want automatic processing for the storage group.

The value for Cycle Start Time must be different from the value for Cycle End Time. When you specify NONE, the value for Cycle End Time must be blank.

Recommendation: If you are running in an OAMplex and specify a cycle start time, specify an OSMC processing system name. Otherwise, object processing for that object backup storage group will start on all systems in the OAMplex at cycle start time.

Cycle End Time

Identifies the end of a window of time when object processing can be started for this object backup storage group.

The function of the cycle end time depends on which cycle window mode is in effect when OAM initializes. The cycle window mode can be specified by using the CYCLEWINDOW keyword for the SETOSMC statement in the CBROAMxx parmlib member (refer to z/OS DFSMS OAM Planning, Installation, and Storage Administration Guide for Object Support). In Start Only mode, the cycle end time identifies the end of a window of time when object processing can be started for this storage group. In Start Stop mode, when the cycle end time has been reached, processing will be the same as if a STOP command had been issued for that storage group. No new work will be scheduled, all work in progress will be allowed to complete.

Specify a value from 0 - 23, or blank. A value from 0 - 23 represents an hour of the day, and is required when a value from 0 to 23 was specified for Cycle Start Time. For example, specify an hour of the day as 00 for midnight; 01 for 1 a.m.; or 23 for 11 p.m.

The value for Cycle End Time must be different from the value for Cycle Start Time. Leave the field blank if you specified NONE for Cycle Start Time.

OSMC Processing System

Specifies an OSMC processing system name, which identifies which OAM system in the sysplex performs OSMC processing for this object backup storage group. This prevents multiple systems from trying to process the same storage group at the same time, especially when the Cycle Start Time parameter is used for automatically starting storage group processing.

Library Names

Specifies up to eight real library names that represent optical libraries, or one–to-eight pseudo library names. The libraries you specify are used to process write requests to the storage group. Names must be valid real or pseudo optical library names defined in the SCDS.

Volume Full Threshold

Specifies the number of free KB triggering volume full processing for an optical volume within the object backup storage group. When the number of free KB falls below the threshold, the object access method marks the optical volume full. If the threshold is reached while OAM is writing an object, OAM continues writing that object until finished. OAM then writes no more objects to that volume. Valid values are from 0 to 9999. This is a required field if a library name is specified.

Drive Start Threshold

Specifies the maximum number of object write requests outstanding for an optical drive in this storage group. When the number of object write requests to this storage group divided by the number of optical drives currently processing requests for this storage group exceeds this threshold, the object access method attempts to start an additional optical drive. Valid values are from 0 to 9999. This is a required field if you specify a library name.

Volume Full at Write Error

Indicates when to mark as full optical volumes within this backup object storage group. If Y, the OAM marks an optical volume full the first time an attempt to write an object on the optical volume fails because not enough space remains on the optical volume. If you specify N, the object access method marks an optical full only when the number of available KB in the user data area falls below the Volume Full Threshold. The volume is also marked full if the optical volume table of contents area is full, regardless of how many KB are remaining in the user data area. This is a required field if you specify a library name.

DEFINE SMS Storage Group Status

Indicates whether you want to change the storage group status. This is a required field. The values are:

Y: (Yes). If you are defining a storage group, the default value is Y and cannot be changed to N. If you specify Y, you will see a panel for changing the storage group status next. See Defining object or object backup storage group statusfor more information.
N: (No). If you are altering a storage group, the default value is N and can be changed to Y or N.

Object tape parameters for object and object backup storage groups are specified with SETOAM statements in the CBROAMxx member of PARMLIB. For more information, see z/OS DFSMS OAM Planning, Installation, and Storage Administration Guide for Object Support.