DFSMSdss temporary data set names

DFSMSdss must allocate temporary data sets to perform certain functions such as copy and restore. The high-level qualifiers of those data set names can be protected, and your installation must ensure that these temporary data sets can be allocated.

Message data set

Allocated by DFSMSdss to store messages. DFSMSdss prints messages by task, rather than intermixing them. This data set is deleted when DFSMSdss completes the operation. System-generated temporary names are used.

Special DEFRAG data set—

Allocated by DFSMSdss to contain information about the DASD extents that are being moved. The data set name is in the following format:

   SYS1.DFDSS.DEFRAG.xxxxxxxx.volser.DUMMY

where xxxxxxxx represents 8 bytes of X'FF', and volser is the volume serial number of the volume being defragmented. The data set is deleted when the DEFRAG or CONSOLIDATE operation ends successfully.

If the operation is interrupted (for example, if DFSMSdss is canceled), the data set is left on the volume. To delete the data set, repeat the DEFRAG or CONSOLIDATE operation. Before doing so, observe the following considerations:

You might need to convert an index VTOC (IXFORMAT) volume to non-indexed VTOC (OSFORMAT) before rerunning the DEFRAG or CONSOLIDATE operation. Otherwise, the volume free space values might be incorrect.
Use the hexadecimal qualifier to prevent the deletion of this data.

Temporary copied data sets

Allocated by DFSMSdss when a copy is performed and deleted when the copy is completed.

The format of the temporary name depends on the number of qualifiers of the data set that is being copied:

Number of qualifiers (`n`)	Temporary name
1	`dsnhlq.Atidasid.chmmsstt`
2	`First 2 qualifiers.Atidasid.chmmsstt`
> 2	`First 3 qualifiers.Atidasid.chmmsstt`

The next to last qualifier Atidasid is: a combination of a fixed "A" character, a task id (tid), and an address space id (asid).

The last qualifier is chmmsstt where c is:

T: Target cluster name
D: Target data component name
I: Target index component name
U: Source cluster name
E: Source data component name
J: Source index component name
P: Source path name
Q: Target path name

and hmmsstt is the time stamp information in low-order hours digits (h), minutes (mm), seconds (ss), and hundredths of a second (tt).

Note: In the course of copying data sets, DFSMSdss renames the source data set using the above conventions. Whenever DFSMSdss renames a data set that is protected by RACF® to a temporary name, a RACF profile must exist for the temporary data set name.

Temporary copied catalogs

Allocated by DFSMSdss when it copies a catalog. When DFSMSdss copies a catalog, two temporary data sets are used.

First, DFSMSdss allocates a temporary data set into which records are temporarily exported with the following name format:

   CATHLQ.EXPORT.Thmmsstt

where,
CATHLQ

First three high-level qualifiers of the catalog being copied

hmmsstt

Time-stamp information in low-order hours digits (h), minutes (mm), seconds (ss), and hundredths of a second (tt)

Second, DFSMSdss allocates a temporary catalog with the following name format:

   CATHLQ.Thmmsstt

where,
CATHLQ

First four high-level qualifiers of the catalog that is being copied

hmmsstt

Time-stamp information in low-order hours digits (h), minutes (mm), seconds (ss), and hundredths of a second (tt)

Dummy data set

Allocated by DFSMSdss when copying or restoring volumes and an indexed VTOC needs to be rebuilt or the volume free-space values need to be recalculated. The data set name is in the following format:

   SYS1.VTOCIX.DSS.TEMP.volser

where volser is the volume serial number of the volume being restored. Allocation of this data set is never successful because DFSMSdss uses dummy allocation values.