Modify storage class definition
Component: | BS2000 |
Functional area: | Pubset and MRSCAT management |
Domain: | MULTI-CATALOG-AND-PUBSET-MGMT |
Privileges: | TSOS |
Function
The MODIFY-STORAGE-CLASS command enables systems support to modify the definition of an existing storage class.
The SM pubset for which the storage class is defined must have been imported to the local system (in exclusive or shared mode).
All the file attributes which are modified for the storage class initially apply to new files assigned to the storage class. An existing file which belongs to the storage class will not be given the modified file attributes of the storage class until they are reassigned to the file in a MODIFY-FILE-ATTRIBUTES command which specifies STORAGE-CLASS=*UPDATE.
Format
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Operands
STORAGE-CLASS-NAME = <composed-name 1..8>
Name of the storage class which is to have its definition modified.
PUBSET = <cat-id 1..4>
Identifies the pubset for which the storage class was created. The pubset must have been imported to the local system (in exclusive or shared mode).
FILE-ATTRIBUTES = *UNCHANGED / *PARAMETERS(...)
Specifies which pubset management requirements, representable in the form of file attributes, are to be modified. These file attributes apply to all new files to which the user assigns the storage class instead of explicit attributes (see the STORAGE-CLASS operand of the CREATE-FILE or MODIFY-FILE-ATTRIBUTES command).
An existing file which belongs to the storage class will not be given the modified file attributes of the storage class until they are reassigned to the file in a MODIFY-FILE-ATTRIBUTES command which specifies STORAGE-CLASS=*UPDATE.
The default value, *UNCHANGED, means that the existing setting of the file attributes in question is left unchanged.
FILE-ATTRIBUTES = *PARAMETERS(...)
Specifies which file attributes are to be modified for files in the given storage class.
IO-ATTRIBUTES = *UNCHANGED / *PARAMETERS(...)
Specifies which performance requirements are to be modified for files in this storage class.
The default value, *UNCHANGED, means that the existing setting of the file attributes in question is left unchanged.
IO-ATTRIBUTES = *PARAMETERS(...)
Performance attributes are determined by the values of the PERFORMANCE and USAGE operands.
PERFORMANCE = *UNCHANGED / *STD / *HIGH / *VERY-HIGH
Specifies the performance attribute for files in this storage class. It indicates the priority required for the I/O operations selected in the USAGE operand.
PERFORMANCE = *STD
No performance requirements are defined for files in this storage class. In this case the USAGE operand has no impact on file processing.
PERFORMANCE = *HIGH
A cache should be used to process files in this storage class (high performance priority).
PERFORMANCE = *VERY-HIGH
A cache should be used to process files in this storage class, and if possible the entire file should be kept permanently in the cache (highest performance priority, only available in the GS cache medium).
USAGE = *UNCHANGED / *READ-WRITE / *WRITE / *READ
Specifies the I/O operations for which enhanced performance (caching) is required. The default is *READ-WRITE, i.e. the requirement applies to both read and write operations.
The requirement may also be applied only to write operations (*WRITE) or only to read operations (*READ).
If the file has no special performance attribute (PERFORMANCE=*STD), the USAGE operand has no impact on processing.
DISK-WRITE = *UNCHANGED / *STD / *IMMEDIATE / *BY-CLOSE
Specifies the time at which data consistency is required for files in this storage class after a write operation.
DISK-WRITE = *STD
The default setting of *STD is equivalent to *IMMEDIATE for permanent files and to *BY-CLOSE for temporary files.
DISK-WRITE = *IMMEDIATE
The data in a file must be in a consistent state immediately on completion of a write operation, so a volatile write cache should not be used to process files in this storage class.
DISK-WRITE = *BY-CLOSE
The data in a file does not have to be in a consistent state until after CLOSE processing, so a volatile write cache may be used to process files in this storage class.
AVAILABILITY = *UNCHANGED / *STD / *HIGH
Specifies availability requirements for files in this storage class.
AVAILABILITY = *STD
There are no special availability requirements.
AVAILABILITY = *HIGH
Files in this storage class are required to have high availability (e.g. storage on mirrored disks).
FILE-PREFORMAT = *UNCHANGED / *BY-PUBSET-DEFAULT / *K / *NK2 / *NK4
Governs the preferred file format for files in this storage class. This specification only applies when the catalog entry is created; it is used to determine the storage location automatically.
As long as the file does not yet have a creation date (CRE-DATE=NONE), the storage location is provisional and may still change in the course of OPEN processing.
FILE-PREFORMAT = *BY-PUBSET-DEFAULT
The pubset-global default applies.
FILE-PREFORMAT = *K
File in this storage class are to be created as K files.
FILE-PREFORMAT = *NK2
File in this storage class are to be created as NK2 files.
FILE-PREFORMAT = *NK4
File in this storage class are to be created as NK4 files.
WORK-FILE = *UNCHANGED / *NO / *YES
Specifies whether files in this storage class are work files.
WORK-FILE = *NO
Files in this storage class are created as normal files.
WORK-FILE = *YES
Files in this storage class are created as work files. Systems support can delete work files at appointed times.
STORAGE-CLASS-INFO = *UNCHANGED / *NONE / <c-string 1..720 with-low>
Systems support can compose a brief text describing storage class attributes. It will typically relate to special pubset management requirements which are defined by systems support but cannot be represented in the form of file attributes. This brief text is included in the output of the SHOW-STORAGE-CLASS command to inform the user of any special properties of the storage class.
STORAGE-CLASS-INFO = *NONE
There is to be no explanatory text for the storage class. If one already exists, it is deleted.
STORAGE-CLASS-INFO = <c-string 1..720 with-low>
A brief text describing special properties of the storage class as defined by systems support. Any existing explanatory text is overwritten.
PROTECTION = *UNCHANGED / *NONE / *BY-GUARDS(...)
Specifies whether access to the storage class is to be controlled by guards.
PROTECTION = *NONE
Access to the storage class is not to be controlled by guards. Any existing guards protection is canceled.
PROTECTION = *BY-GUARDS(...)
Allocation to the storage class and the listing of the storage class definitions are to be controlled by a guard. The guard named next defines conditions under which a user is allowed to access the storage class.
GUARD-NAME = <filename 1..18 without-cat-gen-vers>
Name of the guard.
VOLUME-SET-LIST = *UNCHANGED / *NONE / <composed-name 1..8>
Specifies whether a volume set list is to be assigned to the storage class.
VOLUME-SET-LIST = *NONE
No volume set list is to be assigned to the storage class. Any existing assignment is canceled.
VOLUME-SET-LIST = <composed-name 1..8>
The specifies volume set list is assigned to the storage class. Any existing assignment is canceled.
The volume set list must already exist for this SM pubset.
Return codes
(SC2) | SC1 | Maincode | Meaning |
|---|---|---|---|
0 | CMD0001 | No errors | |
1 | CMD0202 | Syntax error in command | |
32 | CMD0221 | Internal system error | |
64 | CMD0216 | No authorization to issue command | |
64 | DMS148A | Storage class not defined | |
64 | DMS1497 | Invalid file attribute combination | |
64 | DMS148B | Volume set list not defined | |
64 | DMS1485 | Pubset not known | |
64 | DMS1486 | Pubset is not a system-managed pubset | |
64 | DMS1487 | Pubset not available | |
64 | DMS1490 | Storage class management not available for this pubset | |
64 | DMS1483 | Storage class catalog invalid | |
64 | DMS1481 | Error accessing storage class catalog | |
64 | DMS1484 | Volume set list catalog invalid | |
64 | DMS1482 | Error accessing volume set list catalog | |
129 | DMS148D | Not enough class 4/5 memory | |
129 | DMS148E | Error on MSCF connection to master | |
129 | DMS148F | GCF subsystem not ready |