Read/Write serialization scheme

Table 1 shows the serialization scheme used by all operations, except COPYDUMP, for read/write access.
Table 1. Read/Write Access Serialization Scheme
 Item ENQ Major Name ENQ Minor Name ENQ Control, Exclusive (E) or Share (S) ENQ Scope
   For Source HFS Data Sets:
 
 
  followed by:
ADRDSN
 
SYSZDSN
Data set name
 
Data set name
E (see Note 1)
S (see Note 1)
E (see Note 2)
S (see Note 2)
STEP
 
SYSTEMS
   For zFS Data Sets:
On the component during logical data set DUMP or COPY operations: SYSVSAM See Note 3
E (see Note 5)
S (see Note 5)
 SYSTEMS
On the component during physical data set DUMP operations: SYSVSAM See Note 3
E (see Note 1)
S (see Note 1)
 SYSTEMS
On the component during other operations: SYSVSAM See Note 3 E SYSTEMS
On the cluster during logical
DUMP or COPY operations:
 
  followed by:
ADRDSN
 
 
 
SYSDSN
Cluster name
 
 
 
Cluster name
E (see Note 1)
S (see Note 1)
E (see Note 5)
S (see Note 5)
STEP
 
 
 
SYSTEM
On the cluster during other
operations:
 
  followed by:
ADRDSN
 
 
SYSDSN
Cluster name
 
 
Cluster name
E (see Note 1)
S (see Note 1)
E (see Note 1)
S (see Note 1)
STEP
 
  
SYSTEM
   For Non-VSAM Data Sets:
 
 
  followed by:
ADRDSN
 
SYSDSN
Data set name
 
Data set name
E (see Note 1)
S (see Note 1)
E (see Note 1)
S (see Note 1)
STEP
 
SYSTEM
   For GDG Data Sets:
On the GDG base:
 
  followed by:
ADRDSN
 
SYSDSN
GDG base name
 
GDG base name
E (see Note 1)
S (see Note 1)
E (see Note 1)
S (see Note 1)
STEP
 
SYSTEM
On each GDG data set:
 
  followed by:
ADRDSN
 
SYSDSN
Data set name
 
Data set name
E (see Note 1)
S (see Note 1)
E (see Note 1)
S (see Note 1)
STEP
 
SYSTEM
   For VSAM Data Sets:
On each component during data set DUMP or COPY operations: SYSVSAM See Note 3
E (see Note 1)
S (see Note 1)
 SYSTEMS
On each component during other operations: SYSVSAM See Note 3 E SYSTEMS
On the cluster:
 
  followed by:
ADRDSN
 
SYSDSN
Cluster name
 
Cluster name
E (see Note 1)
S (see Note 1)
E (see Note 1)
S (see Note 1)
STEP
 
SYSTEM
   For Integrated Catalog Facility Catalogs:
In addition to the above VSAM data set information: SYSIGGV2 Catalog name E SYSTEMS
   On the volume: SYSVTOC Volume serial number E SYSTEMS
   For VVDS Data Sets:
On each data set:
  Input access:
  Output access:
 SYSZVVDS SYS1.VVDS.Vvolser
 
S
E
 SYSTEMS
Note:
  1. If the selected control for the ENQs is EXCLUSIVE or SHARE, the SHARE keyword determines the type of control. If SHARE is not specified, exclusive control of the data set is obtained. Whereas, if SHARE is specified, shared control of the data set is obtained.

    If shared control is obtained for a VSAM data set because the SHARE keyword was specified, other programs are able to obtain read access, but not write access, to the data set, while it is being processed. The SHARE keyword is honored for VSAM data sets only during DUMP and COPY processing, and only for VSAM data sets that are defined with SHARE options other than (1,3) or (1,4).

  2. For a source HFS data set, DFSMSdss ignores DYNALLOC. If you specify DELETE, then DFSMSdss attempts to get an exclusive SYSZDSN enqueue. If you do not specify DELETE, then DFSMSdss attempts to get a shared SYSZDSN enqueue.
  3. If DYNALLOC is used:

    For a source HFS data set, DFSMSdss ignores DYNALLOC.

    For non-VSAM data sets and GDG bases, instead of ENQ, the data set is dynamically allocated automatically, with a disposition of OLD if SHARE is not used; otherwise, SHARE is the disposition.

    For VSAM data sets, in addition to the ENQ on the components, the cluster is allocated dynamically just as for non-VSAM data sets.

  4. The minor name used for enqueuing VSAM components consists of the following: component name, catalog name, L1, L2, L3, A (where L1 is the total length of the minor name, L2 is the component name length, and L3 is the catalog name length).

    On a data set DUMP, data set RESTORE, data set COPY, and DEFRAG operation, an enqueue is performed once with the character A=I and iteratively with A=O.

  5. If you specify DELETE, then DFSMSdss attempts to get exclusive control of the zFS. If you do not specify DELETE, then DFSMSdss attempts to get a shared control of the zFS.
Programming Interface information: Although the ENQ on the major name ADRDSN is mostly intended to coordinate access to data sets between multiple DFSMSdss commands, it might be necessary for application programs that invoke DFSMSdss to make use of the ENQ; data sets that are serialized by the application program using dynamic allocation or an ENQ on the major name SYSDSN could be processed by DFSMSdss unless the application uses the ENQ on ADRDSN.
Table 2. Resource Serialization
  Function Data Set Type Volume Level Serialization VTOC   VVDS Data Set Level Serialization (ENQ or DYNALLOC)
COMPRESS Non-VSAM
Yes     N/A
 DSName
CONSOLIDATE
Non-VSAM
VSAM
Yes     N/A
Yes     Yes
DSName
Component and Cluster Names
CONVERTV Non-VSAM
Yes     N/A
 DSName
Data Set COPY
Non-VSAM
VSAM
Yes     N/A
Yes     Yes
DSName
Component and Cluster Names
DEFRAG
Non-VSAM
VSAM
Yes     N/A
Yes     Yes
DSName
Component and Cluster Names
Full DUMP
Non-VSAM
VSAM
Yes     N/A
Yes     Yes
N/A
N/A
Data Set DUMP
Non-VSAM
VSAM
Yes     N/A
Yes     Yes
DSName
Component and Cluster Names
Data Set PRINT
Non-VSAM
VSAM
Yes     N/A
Yes     Yes
DSName
Component Name
Tracks PRINT
 N/A
Yes     N/A
 N/A
RELEASE
Non-VSAM
VSAM
Yes     N/A
Yes     Yes
DSName
Component and Cluster Names
Full RESTORE
Non-VSAM
VSAM
Yes     N/A
Yes     Yes
N/A
N/A
Data Set RESTORE
Non-VSAM
VSAM
N/A     N/A
N/A     Yes
DSName
Component and Cluster Names
Notes for Table 2: