SETOAM keyword definitions for STORAGEGROUP subparameters

DATACLASS(name)

An optional subparameter of the STORAGEGROUP parameter that specifies the SMS data class to be associated with this Object or Object Backup storage group. Usage of the DATACLASS keyword on the SETOAM statement allows an installation to affect things such as, TDSI, and the tape volume expiration date on an individual Object or Object Backup storage group level. If you do not specify DATACLASS on the SETOAM statement for a specific storage group, but you do specify DATACLASS at the global level of the SETOAM statement, the global OAM DATACLASS specification applies to the specific storage group.

In an IBM tape library environment, specify the SETOAM DATACLASS parameter using a data class to request the desired media type or recording technology. To request tape data encryption in the tape library environment and in the stand-alone environment, use DATACLASS to request an encryption recording format; you can also specify the encryption key labels and encoding mechanisms using data class. In addition, you can specify DATACLASS to take advantage of performance scaling or performance segmentation in an IBM tape library environment and also in the stand-alone environment. Use the performance options in the data class to improve the random retrieval rate of primary objects in Object storage groups. For objects written to Object Backup storage groups, you can specify a data class that does not specify performance scaling, then you can use the full capacity of the volume.

Note: Tape data encryption is supported on the 3592, starting with the 3592 Model E05. Performance scaling and performance segmentation is supported on all the 3592 models, starting with the 3592 Model J1A.

Recommendation: Do not allow ACS routines to assign or change the data class assignment of an OAM tape volume. The data class for OAM tape volumes is determined by the SETOAM statement of the CBROAMxx PARMLIB member at MVS scratch tape allocation. The SETOAM statement provides this information at the storage group level or at the OAM global level, and it best suits the requirements for the tape volume being allocated. Allowing ACS routines to alter this specification could create unexpected consequences (for example, no compaction of the data when the SETOAM statement specified compaction). It is your installation responsibility to write ACS routines to not alter the data class construct for OAM tape volumes.

DEMOUNTWAITTIME(seconds)

An optional subparameter of the STORAGEGROUP parameter. It specifies the time, in seconds, that OAM waits before demounting and deallocating a tape drive (allocated for the storage group specified with the STORAGEGROUP parameter), that OAM is currently not using. For seconds, specify a decimal number between 1 and 9999. When the time interval expires, OAM rewinds and unloads the currently mounted tape cartridge and demounts and deallocates the device. The default for this optional parameter is 120 seconds.

Some circumstances might affect how this parameter is enforced:

If a new tape drive allocation request arrives and OAM has already used the maximum number of tape drives (MAXTAPERETRIEVETASKS + MAXTAPESTORETASKS), then OAM ignores the DEMOUNTWAITTIME and deallocates this drive to allocate another.
If OAM is canceled, a DEMOUNT occurs, and DEMOUNTWAITTIME is ignored.
If a request to vary the drive offline is sent while the DEMOUNTWAITTIME is in effect for that drive in an OAM session, the drive cannot vary offline until the specified DEMOUNTWAITTIME elapses.
If OAM finishes reading and writing to a tape before the DEMOUNTWAITTIME elapses, a demount, unload, rewind, or release of the allocated drive cannot take place until the specified DEMOUNTWAITTIME is complete.

L2DATACLASS(name)

An optional subparameter of the STORAGEGROUP parameter that specifies the SMS data class to be associated with this object storage group when you use tape sublevel 2. Tape sublevel is associated with the OAM Sublevel parameter specified in the SMS storage class construct. Usage of the L2DATACLASS keyword on the SETOAM statement allows an installation to affect things such as, TDSI, and the tape volume expiration date on an individual Object storage group level. If you do not specify L2DATACLASS on the SETOAM statement for a specific object storage group, but you do specify L2DATACLASS at the global level of the SETOAM statement, the global L2DATACLASS specification applies to the specific object storage group.

Note: The L2DATACLASS keyword can not be associated with an Object Backup storage group.

In an IBM tape library environment, specify the SETOAM L2DATACLASS parameter using a data class to request the desired media type or recording technology. To request tape data encryption in the tape library environment and in the stand-alone environment, use L2DATACLASS to request an encryption recording format; you can also specify the encryption key labels and encoding mechanisms using data class. In addition, you can specify L2DATACLASS to take advantage of performance scaling or performance segmentation in an IBM tape library environment and also in the stand-alone environment. Use the performance options in the data class to improve the random retrieval rate of primary objects in Object storage groups. For objects written to Object Backup storage groups, you can specify a data class that does not specify performance scaling, then you can use the full capacity of the volume.

L2TAPEUNITNAME(unitname)

A required subparameter of the STORAGEGROUP parameter, if you use the tape sublevel 2 function. Tape sublevel is associated with the OAM Sublevel parameter specified in the SMS storage class construct. This subparameter specifies the type of tape drive that OAM uses when writing data to an Object storage group using Tape Sublevel 2. This L2TAPEUNITNAME is the MVS unit name that OAM uses to initially allocate a scratch tape when an object is stored to this object storage group and stored on a tape volume. For unitname, specify the name of a valid MVS esoteric (group of devices defined to a group name) or a generic unit name. Valid generic unit names are:

3480—a base 3480 device
3480x—a 3480 device with the IDRC feature, or a base 3490 device
3490—a 3490E device
3590-1—a 3590 device (or a device that emulates a 3590-1)

The unit name specified is associated with each tape volume used for output during the process of writing objects to tape that belong to a specified object storage group. This unit name is saved in the corresponding rows in the TAPEVOL table for each of these tape volumes, and is used during later allocations of these tape volumes for either reading or writing processing.

Note: The L2TAPEUNITNAME keyword cannot be associated with an Object Backup storage group.

L2TAPEUNITNAME is a required keyword when using tape sublevel 2, and is specified for all tape sublevel 2 allocations. In the automated tape library dataservers and manual tape libraries, this information might be used by the ACS filter routines, but is not required for device allocation. In the stand-alone environment, this information is critical in the allocation decision making process.

Note:

Even though a tape unit name is specified for the group, the ACS routines (for environment ALLOC), can override the L2TAPEUNITNAME specification by assigning the allocation to a Tape storage group, thereby steering the allocation into an ATLDS or an MTL.
When OAM requests a mount for a generic tape with a L2TAPEUNITNAME of 3480, it accepts the 3480 tape drive chosen regardless of whether that tape drive has IDRC. MVS Allocation does not use the JCL or dynamic allocation parameter for compaction when determining device eligibility. If tape compaction is requested, and the tape is mounted on a 3480 tape drive that does not have IDRC, allocation fails. To prevent this failure, OAM does not allow tape compaction with a generic L2TAPEUNITNAME of 3480. OAM uses the NOTAPECOMPACTION keyword with all data for this L2TAPEUNITNAME.

Using Esoteric Unit Names: To ensure that objects written on any drive in the esoteric group can be read on any drive in the same esoteric group, OAM does not allow a mixed esoteric unit name that consists of different device types; for example, 3590-1 and 3490E. Avoid using an esoteric unit name that consists of tape drives that write in different recording technologies; for example, a 3590 Model H and a 3590 Model E. Depending on which emulation mode is being used, both drives appear as though they have the same device type (3590-1 or 3490E). However, the read/write request might fail if MVS allocation selects an incompatible tape drive.

MAXTAPERETRIEVETASKS(tasks)

An optional subparameter of the STORAGEGROUP parameter that specifies the maximum number of tape drives used for reading objects from tape volumes belonging to a specific Object or Object Backup storage group. This parameter specifies the maximum number of tasks within the OAM address space that can concurrently read objects from tape for the storage group specified with the STORAGEGROUP parameter. This subparameter and the MAXTAPESTORETASKS subparameter control the maximum number of tape drives that can be concurrently allocated to the OAM address space for reading from and writing to tape volumes belonging to the specified Object or Object Backup storage group. For tasks, specify a decimal number between 1 and 100.

The value specified with the MAXTAPERETRIEVETASKS subparameter of the STORAGEGROUP parameter for a specific Object or Object Backup storage group cannot exceed the global maximum number of tape retrieve tasks specified with the MAXTAPERETRIEVETASKS parameter of the SETOAM statement. If it does, an error message is issued, and the SETOAM statement is rejected. If you do not specify this subparameter on any SETOAM statement, the OAM default is 1.

MAXTAPESTORETASKS(tasks)

An optional subparameter of the STORAGEGROUP parameter that specifies the maximum number of tape drives used for writing objects to tape volumes belonging to a specific Object or Object Backup storage group. This parameter specifies the maximum number of tasks within the OAM address space that can concurrently write objects to tape volumes belonging to the Object or Object Backup storage group specified with the STORAGEGROUP parameter. This subparameter and the MAXTAPERETRIEVETASKS subparameter control the maximum number of tape drives that can be concurrently allocated to the OAM address space for writing to and reading from tape volumes belonging to the specified Object or Object Backup storage group. For tasks, specify a decimal number between 1 and 100.

The value specified with the MAXTAPESTORETASKS subparameter of the STORAGEGROUP parameter for a specific Object or Object Backup storage group, cannot exceed the global maximum number of tape store tasks specified with the MAXTAPESTORETASKS parameter of the SETOAM statement. If it does, an error message is issued, and the SETOAM statement is rejected.

Requirement: To use more than one tape drive for a storage group to write object data to tape, the TAPEDRIVESTARTUP threshold must be low enough to trigger the startup of the additional tape drive. This threshold is a value (in megabytes) of write data pending for this storage group. See the discussion concerning TAPEDRIVESTARTUP on page TAPEDRIVESTARTUP(threshold in megabytes) for more information.

SGMAXRECYCLETASKS(nn)

An optional parameter that you can specify at the storage group level. The nn is the maximum number of MOVEVOL tasks that can be run concurrently by the RECYCLE function for a storage group. The value for SGMAXRECYCLETASKS cannot exceed the value for MAXRECYCLETASKS. Valid values for nn are 0 - 15. The default is 1 if no value is specified. A value of 0 indicates that no RECYCLE operations can be run at the storage group level specified.

If you only want to recycle volumes from one group, the setting for all other groups would be 0 to ensure that the group with a non-zero value receives all the recycling processing.

If you specify a value for a group that is higher than the value for another group, the system selects more of the volumes to recycle from the group with the higher value. However, RECYCLE processing might be working with the original order of volumes that are sorted by the amount of valid data for each volume, and might select volumes from other groups to satisfy the limit before it processes the higher-value group.

SGMAXTAPERETRIEVETASKS(tasks)

An optional parameter you can be specify at the storage group level only. When you specify this keyword at a storage group level, it is identical to the MAXTAPERETRIEVETASKS keyword. This keyword SGMAXTAPERETRIEVETASKS is the preferred naming convention, however, for compatibility the MAXTAPERETRIEVETASKS keyword continues to be maintained.

SGMAXTAPERETRIEVETASKS(tasks) and its alternate MAXTAPERETRIEVETASKS(tasks) provide an optional subparameter of the STORAGEGROUP parameter that specifies the maximum number of tape drives used for reading objects from tape volumes belonging to a specific Object or Object Backup storage group. This parameter specifies the maximum number of tasks within the OAM address space that can concurrently read objects from tape for the storage group specified with the STORAGEGROUP parameter. The SGMAXTAPERETRIEVETASKS subparameter and the SGMAXTAPESTORETASKS subparameter control the maximum number of tape drives that can be concurrently allocated to the OAM address space for reading from and writing to tape volumes belonging to the specified Object or Object Backup storage group. For tasks, specify a decimal number between 1 and 100. The value specified with the SGMAXTAPERETRIEVETASKS keyword (or MAXTAPERETRIEVETASKS subparameter of the STORAGEGROUP parameter for a specific Object or Object Backup storage group) cannot exceed the global maximum number of tape retrieve tasks specified with the MAXTAPERETRIEVETASKS parameter of the SETOAM statement. If it does exceed, an error message is issued, and OAM initialization is terminated. If you do not specify this subparameter on any SETOAM statement, the OAM default is 1.

The F OAM,UPDATE,SETOAM command can be used to dynamically update the SGMAXTAPERETRIEVETASKS value. No restart of the OAM address space is required.

SGMAXTAPESTORETASKS(tasks)

An optional parameter that you can specify at the storage group level only. This keyword is identical to the MAXTAPESTORETASKS keyword when specified at a storage group level. This keyword SGMAXTAPESTORETASKS is the preferred naming convention, however the keyword MAXTAPESTORETASKS is maintained for legacy compatibility.

SGMAXTAPESTORETASKS(tasks) and its alternate MAXTAPESTORETASKS(tasks) provide an optional subparameter of the STORAGEGROUP parameter that specifies the maximum number of tape drives used for writing objects to tape volumes belonging to a specific Object or Object Backup storage group. This parameter specifies the maximum number of tasks within the OAM address space that can concurrently write objects to tape volumes belonging to the Object or Object Backup storage group specified with the STORAGEGROUP parameter. This subparameter and the SGMAXTAPERETRIEVETASKS subparameter control the maximum number of tape drives that can be concurrently allocated to the OAM address space for writing to and reading from tape volumes belonging to the specified Object or Object Backup storage group. For tasks, specify a decimal number between 1 and 100. The value specified with the SGMAXTAPESTORETASKS keyword (or the MAXTAPESTORETASKS subparameter of the STORAGEGROUP parameter for a specific Object or Object Backup storage group), cannot exceed the global maximum number of tape store tasks specified with the MAXTAPESTORETASKS parameter of the SETOAM statement. If it does exceed, an error message is issued, and OAM initialization is terminated.

The F OAM,UPDATE,SETOAM command can be used to dynamically update the SGMAXTAPESTORETASKS value. No restart of the OAM address space is required.

TAPEUNITNAME(unitname)

A required subparameter of the STORAGEGROUP parameter that specifies the type of tape drive that OAM uses when writing data to an Object or Object Backup storage group. This TAPEUNITNAME is the MVS unit name that OAM uses to initially allocate a scratch tape when an object is stored to this Object or Object Backup storage group and stored on a tape volume. For unitname, specify the name of a valid MVS esoteric (group of devices defined to a group name) or a generic unit name. Valid generic unit names are:

3480—a base 3480 device
3480x—a 3480 device with the IDRC feature, or a base 3490 device
3490—a 3490E device
3590-1—a 3590 device (or a device that emulates a 3590-1)

The unit name specified is associated with each tape volume used for output during the process of writing objects to tape that belong to a specified Object or Object Backup storage group. This unit name is saved in the corresponding rows in the TAPEVOL table for each of these tape volumes, and is used during later allocations of these tape volumes for either reading or writing processing.

TAPEUNITNAME is a required keyword, and is specified for all allocations. In the automated tape library dataservers and manual tape libraries, this information might be used by the ACS filter routines, but is not required for device allocation. In the stand-alone environment, this information is critical in the allocation decision-making process.

Note:

Even though a tape unit name is specified for the group, the ACS routines (for environment ALLOC), can override the TAPEUNITNAME specification by assigning the allocation to a Tape storage group, thereby steering the allocation into an ATLDS or an MTL.
When OAM requests a mount for a generic tape with a TAPEUNITNAME of 3480, it accepts the 3480 tape drive chosen regardless of whether that tape drive has IDRC. MVS Allocation does not use the JCL or dynamic allocation parameter for compaction when determining device eligibility. If tape compaction is requested, and the tape is mounted on a 3480 tape drive that does not have IDRC, allocation fails. To prevent this failure, OAM does not allow tape compaction with a generic TAPEUNITNAME of 3480. OAM uses the NOTAPECOMPACTION keyword with all data for this TAPEUNITNAME.

TAPECOMPACTION | NOTAPECOMPACTION

Specify either the optional TAPECOMPACTION or NOTAPECOMPACTION subparameter of the STORAGEGROUP parameter. These parameters specify whether the objects for this storage group are to be written in compacted or noncompacted format. See Table 1 for an example of this selection process.

TAPECOMPACTION specifies that the compaction feature of the tape drive is enabled when OAM is writing objects to tape which belong to the specified Object or Object Backup storage group. This parameter is ignored if the unit name specified with the TAPEUNITNAME parameter is a mixed esoteric group.

If you specify an esoteric unit name for a mixed esoteric group that consists of at least one IBM 3480 tape drive without the IDRC feature and one IBM 3480 or 3490 tape drive with the IDRC feature, the TAPECOMPACTION keyword is ignored and the NOTAPECOMPACTION keyword is assumed.

To enable tape compaction, perform one of the following tasks as appropriate:

Specify the TAPECOMPACTION keyword on the SETOAM statements in the CBROAMxx PARMLIB member.
Omit the TAPECOMPACTION and the NOTAPECOMPACTION keywords on the SETOAM statements in the CBROAMxx PARMLIB member and specify a DATACLASS on the SETOAM statement. In the definition of the data class (specified with the DATACLASS keyword on the SETOAM statement), specify a COMPACTION option of "YES".
Omit the TAPECOMPACTION and NOTAPECOMPACTION keywords on the SETOAM statements in the CBROAMxx PARMLIB member and do not specify a DATACLASS keyword on the SETOAM statements. Instead, specify the COMPACT=YES option in the DEVSUPxx PARMLIB member processed during IPL.

NOTAPECOMPACTION specifies that the compaction feature of the tape drive is disabled when OAM is writing objects to tape belonging to the specified Object or Object Backup storage group.

If you do not specify this subparameter on any SETOAM statement, the OAM default for the specified Object or Object Backup storage group is determined from the DATACLASS associated with this storage group. To use either tape compaction or no tape compaction, specify the DATACLASS with either TAPECOMPACTION or NOTAPECOMPACTION. If no DATACLASS is associated with this storage group or if the DATACLASS associated with this storage group has a blank TAPECOMPACTION specification, then whether tapes added to this storage group will use the compaction feature is determined by the DEVSUP parameter defaults provided during the allocation process.

Table 1. Example of the TAPECOMPACTION / NOTAPECOMPACTION Selection Process
Was TAPECOMPACTION or NOTAPECOMPACTION specified?
YES	Do what is specified.
NO	Check data class specification.
Was DATACLASS specified?
YES	Was compaction either YES or NO? YES Do what is specified. NO Do what is specified.
NO	DATACLASS was not specified, did not apply, or had a blank compaction specification. Consider the DEVSUP specification.
Is there a DEVSUP specification?
YES	Do what is specified.
NO	If 3480, NOTAPECOMPACTION used. If 3480x or 3490, TAPECOMPACTION used. If 3590-1, TAPECOMPACTION used.

Requirement: If you want to change the TAPECOMPACTION | NOTAPECOMPACTION attribute associated with the storage group and you want OAM to only write data in the new format, you must update the tape volume table using the MODIFY OAM,UPDATE,VOLUME,volser,WRITABLE,N command (or by using SPUFI while the OAM address space is not active) to mark the existing tape volumes in the storage group unwritable. You can update the SETOAM TAPECOMPACTION parameter by using the MODIFY OAM,UPDATE,SETOAM,scope,TCOMP,Y command or by updating the CBROAMxx member of PARMLIB and restarting the OAM address space.

TAPEDRIVESTARTUP(threshold in megabytes)

An optional subparameter of the STORAGEGROUP parameter that specifies the drive startup threshold used for writing objects to tape volumes belonging to a specific Object or Object Backup storage group. The parameter indicates when OAM is to start the use of another tape drive for writing objects to tape volumes belonging to the storage group specified with the STORAGEGROUP parameter. When the number of MB of object data waiting to be written to tape is divided by the number of tape drives currently writing object data to tape exceeds the threshold specified by threshold in megabytes, OAM attempts to use another tape drive to write object data to the specified Object or Object Backup storage group.

However, the maximum number of tape drives being used by OAM to write object data to a specific Object or Object Backup storage group is limited by the value specified with the MAXTAPESTORETASKS subparameter of the STORAGEGROUP parameter on the SETOAM statement. The limit specified with this subparameter will never be exceeded.

Additionally, the maximum number of tape drives being used by OAM to write object data to all Object or Object Backup storage groups is limited by the value specified with the global MAXTAPESTORETASKS parameter of the SETOAM statement. The limit specified with this parameter will never be exceeded.

For threshold in megabytes (MB), specify a decimal number between 1 and 9999. If you do not specify this subparameter on any SETOAM statement, the OAM default is 9999.

Requirement: Drive startup threshold in an optical environment is determined differently than the threshold in a tape storage environment. See the discussion concerning DRIVE STARTUP THRESHOLD for more information.

TAPEEXPIRATION(YYYY/DDD)

An optional subparameter of the STORAGEGROUP parameter that specifies the year and date (YYYY/DDD) assigned to the data sets on OAM object tape volumes belonging to a specific Object or Object Backup storage group for expiration purposes where:

YYYY is a four-digit number that specifies a year from 1900 through 2155
DDD is a three-digit number that specifies a day from 001 through 366

The TAPEEXPIRATION date for the data sets on the tape volumes belonging to the Object or Object Backup storage group overrides the expiration date defined in the DATACLASS parameter for these data sets.

If you specify the TAPEEXPIRATION date for the data sets on the tape volumes belonging to the specific Object or Object Backup storage group as the current date or a date preceding the current system date, the data sets are considered previously expired and are therefore eligible for immediate replacement. OAM issues the CBR0317I message to allow you to change the TAPEEXPIRATION value in the SETOAM statement of the CBROAMxx PARMLIB member being used, if necessary.

Expiration dates of 1999/365 and 1999/366 are considered "never-scratch" dates. Data sets with these expiration dates are not deleted or written over. Check with your tape management system to determine what "never-scratch" date should be specified as the TAPEEXPIRATION date and for other policy-type specifications that are needed in the tape management system to indicate that the tapes and data are being externally managed by OAM. For example, if you are using DFSMSrmm to manage OAM objects on tape, the following vital record specifications, shown in TSO/E format, might be appropriate:

RMM ADDVRS DSNAME('OAM.PRIMARY.DATA') COUNT(99999) LOCATION(HOME)
RMM ADDVRS DSNAME('OAM.BACKUP.DATA') COUNT(99999) LOCATION(HOME)
RMM ADDVRS DSNAME('OAM.BACKUP2.DATA') COUNT(99999) LOCATION(HOME)
RMM ADDVRS DSNAME('OPEN') JOBNAME(oamtaskname) COUNT(99999) LOCATION(HOME
RMM ADDVRS DSNAME('ABEND') JOBNAME(oamtaskname) COUNT(99999) LOCATION(HOME)

The above DSNAME examples are data set names without DSNWITHSGNAME specified in the SETOAM statement. If DSNWITHSGNAME were specified, the storage group name would be appended as the data set name's low level qualifier. The JOBNAME value is the name of the job and started task for the OAM address space that opens the tape data sets.

TAPEFULLTHRESHOLD(kilobytes)

An optional subparameter of the STORAGEGROUP parameter that specifies a numeric value of 0 through 999 999 representing the number of KB of available free space allowed for each volume belonging to the Object storage group specified in the STORAGEGROUP parameter. When the number of KB of free space for a tape volume falls below the TAPEFULLTHRESHOLD subparameter for the storage group to which that volume belongs, the volume is marked full and is not used for any further write requests. The default value for this parameter is zero.

Recommendation: You should select a threshold value that allows tape volumes to be marked full in a consistent manner. Consider the size of the objects stored, and if the size of the objects is consistent, select a threshold value for the storage group that is slightly larger than that size. If volumes are not being selected for new objects and they are not being marked full, increase the value of this parameter.

During OAM initialization, the tape volume full status is checked with the TAPEFULLTHRESHOLD subparameter to determine the volume’s free space and the TAPEPERCENTFULL subparameter to determine the volume’s percent full status. The volume full status is changed from full to not full if:

Free space for the volume is greater than the TAPEFULLTHRESHOLD subparameter value and the volume percent full value is less than the TAPEPERCENTFULL subparameter.

The volume full status is changed from not full to full if:

Free space for the volume is less than or equal to the TAPEFULLTHRESHOLD subparameter value or the volume percent full value is equal to or greater than the TAPEPERCENTFULL subparameter value.

TAPEPERCENTFULL(percent)

An optional subparameter of the STORAGEGROUP parameter that specifies the percent full utilization used for writing objects to tape volumes belonging to a specific Object or Object Backup storage group. This parameter indicates at what percent of utilization OAM stops writing objects to tape volumes belonging to the storage group specified with the STORAGEGROUP parameter on the SETOAM statement.

When the tape volume utilization percentage for a tape volume belonging to an Object or Object Backup storage group reaches or exceeds the threshold specified by percent, OAM stops writing objects to the tape volume. The tape volume is marked full and another tape volume belonging to the specified Object or Object Backup storage group is selected for the continuation of writing objects to that storage group. If there are no tape volumes in the storage group with enough space to accommodate the object to be written, or if TAPEDRIVESTARTUP processing is attempting to start an additional tape drive and an additional scratch tape is required to start that drive, an OAM scratch tape is added to the group. If there are no OAM scratch tapes available, then an MVS scratch tape is requested and added to the Object or Object Backup storage group.

For percent, specify a decimal number between 1 and 100. If you do not specify this subparameter on any SETOAM statement, the OAM default is 100.

The TAPEPERCENTFULL subparameter is retroactive for the Object and the Object Backup storage groups defined in the ACDS. Whenever OAM is started and the TAPEPERCENTFULL for an Object or Object Backup storage group which is currently defined in the ACDS has been changed since the last time OAM was started, that new TAPEPERCENTFULL value is applied to all tapes which currently belong to the subject STORAGEGROUP. This situation means that several changes might be made to the tape volume table rows for the volumes in the storage group:

The free space (FRESPACE) for a volume might increase or decrease depending on whether the TAPEPERCENTFULL is increased or decreased.
The volume full indicator (FULL) might change from full to not full, or from not full to full, depending on whether the TAPEPERCENTFULL is increased or decreased.

The adjustment is made to all affected tapes regardless of whether the tapes were previously marked full, unreadable, or unwritable. If new volumes are added to the storage group, they conform to the new TAPEPERCENTFULL value specified on the SETOAM statement that is being used for the current OAM initialization.

Requirement: If you modify the TAPEPERCENTFULL value using the MODIFY OAM,UPDATE command, a volume you have marked full might be subsequently marked not full. This is because the volume's current tape full percentage is less than the value of the TAPEPERCENTFULL parameter on the SETOAM statement. If you intend to mark the volumes in an Object or Object Backup storage group as full, then you must increase the value of the volume's percent full value (PFULL) to 100.

NOT programming interface information

Note: OAM can mark a tape volume full when:

An 18-track tape reaches sector 69.
A 36-track tape reaches sector 1 on the second wrap. This is done to prevent OAM from falling into EOV processing.

End of NOT programming interface information

For optical storage, specify the volume full threshold parameter to determine the threshold value for an optical volume. See VOLUME FULL THRESHOLD for information on the volume full threshold parameter for optical volumes.