Page 3 of the Management Class
Define panel contains the management
class backup attributes. (For objects, see Defining class transition attributes.)
- Backup Frequency
-
For DFSMShsm, the Backup Frequency attribute
specifies how many days must elapse before DFSMShsm can back up data
sets that have changed since the last backup. If you want to back
up changed data sets every time that DFSMShsm processes the volumes
containing them, specify 0. The default is 1.
For
DFSMSdfp OAM object support, if Auto Backup = 'Y', the Backup
Frequency attribute specifies when the first backup
copy of an
object is to be written. If 0 is specified, then OAM will schedule
a backup copy at the time the object is initially stored. If non-zero
is specified then OAM will schedule backup copy(s) to be written during
the OAM Management Component (OSMC) storage group processing cycle.
The default is 1.
- Number of Backup
Vers
- Specifies
the maximum number of backup versions to retain for
a data set. The default is 2 if the data set still exists and 1 if
it has been deleted.
Creating a new backup version
when the number of backup versions already equals the value specified
for the appropriate Number of Backup Vers attribute
(Data Set Exists) causes the oldest version of the appropriate type
to be deleted.
The number of backup versions is used to determine
whether OAM should write one or two backup copies of the objects,
when you activate the SECONDBACKUPGROUP function for objects using
SETOSMC in the CBROAMxx member of PARMLIB.
If the number
of backup versions is greater than 1 and AUTO BACKUP is Y, OAM will
create two backup copies. When the original object is expired or deleted,
all backup copies are also deleted.
- Retain
Days Only Backup Ver
- Indicates how
many days to keep the most recent backup version
of a deleted data set, starting from the day DFSMShsm detects it has
been deleted. This attribute applies only when a data set no longer
exists on primary (level 0) or migrated (levels 1 and 2) storage.
The default is 60.
This field does not apply to objects. Backup
copies of objects are not retained when the original object is deleted.
- Retain Days Extra Backup Vers
- Indicates how many days to keep backup
versions other than the
most recent one, starting from the day backups were created. It applies
only when more than one backup version exists, and when a data set
has low activity. This attribute applies whether the data set has
been deleted or not. The default is 30.
The number
of extra versions is the number of backup versions minus one. If you
specify 1 for Number of Backup Vers, there
are no extra versions.
For example, if you specify 3 for Number of Backup
Vers (Data Set Deleted), the number of "extra" versions for deleted
data sets is 2. These 2 versions are managed according to the Retain
Days Extra Backup Vers attribute. Any other
versions that may have existed when the data set was deleted will
be deleted the next time EXPIREBV is processed.
- Admin or User Command Backup
- Indicates if both the end user and the storage
administrator
can issue command backups of the data sets in this management class,
if only the storage administrator can, or if neither of them can.
The Admin or User command Backup field is required, and has a default
value of BOTH. Otherwise, the remaining fields are optional.
- BOTH
- Indicates that both storage administrators
and users can perform
command backups against these data sets.
- ADMIN
- indicates that only storage administrators can perform command
backups against these data sets.
- NONE
- indicates that neither storage administrators or end users can
perform command backups.
If you specify BOTH or ADMIN in the Admin or User Command
Backup field, the remaining fields on this panel are required. If
the value is BOTH or ADMIN, then AUTO BACKUP specifies whether these
data sets are eligible for automatic backup.
- Auto Backup
- Is required,
and has a default value of Y. If you specify Y
in the Auto Backup field, the remaining fields on this panel are required.
Otherwise, the remaining fields are optional.
OAM backs up the object
during the first management cycle after the object is assigned to
a management class requiring backup. This can occur when the object
is stored or when its management class is changed by you or by a class
transition. Backup copies of an object are deleted when the object
is deleted. No archived copy is saved.
- Backup
Copy Technique
- Specifies whether concurrent
copy should be used during data
set backup processing.
When deciding whether or not to use concurrent
copy for a particular dump or copy operation, you need to decide why
you are making a copy of the data. If the intention of the copy is
to capture a point-in-time image of the data at a specific time, concurrent
copy might not be appropriate. When you use concurrent copy there
is always a chance that a dump or copy operation does not complete
once you have started to make updates to the data. If this happens,
the specific point-in-time is lost and you might not be able to recover
an image of the data at that time.
- AR|R
- indicates DFSMSdss keyword CONCURRENT(ANYREQ)
- VR
- indicates DFSMSdss keyword CONCURRENT(VIRTUALREQ)
- CR
- indicates DFSMSdss keyword CONCURRENT(CACHEREQ)
- AP|P
- indicates DFSMSdss keyword CONCURRENT(ANYPREF)
or CONCURRENT
- VP
- indicates DFSMSdss
keyword CONCURRENT(VIRTUALPREF)
- CP
- indicates
DFSMSdss keyword CONCURRENT(CACHEPREF)
- S
- indicates not specifying CONCURRENT keyword to DFSMSdss. This
is the default.
Recommendation: Avoid specifying
conflicting conditions in the storage class and the management class.
For example, if you specify Backup Copy Technique as R (required)
in the management class and Accessibility as NOPREF in the storage
class, you would be requesting concurrent copy for backup while having
placed the data set on a device that does not support concurrent copy,
which would result in the backup failing. Specifying the backup copy
technique option in the management class in no way affects the placement
of data sets on a concurrent copy volume.
After
you specify the backup attributes, issue the DOWN command to see the
next page of the Management Class Define panel, on which you can specify
the object attributes.