Creating a file generation

Before opening a file generation, openUTM checks whether the respective file generation already exists. If the file generation does not exist, then openUTM creates it. You can also create the file generation yourself to define different values for PRIMARY-ALLOCATION and SECONDARY-ALLOCATION.

Creation of the file generation by openUTM

Depending on whether the FGG was created on PUBLIC or PRIVATE DISK, openUTM issues one of the following commands internally:

• FGG on PUBLIC DISK

  /CREATE-FILE-GENERATION                             -
  /   GENERATION-NAME = fgg-name(*gen)                -
  /  ,SUPPORT = *PUBLIC-DISK(                         -
  /      SPACE = RELATIVE(                            -
  /         PRIMARY-ALLOCATION = prim-alloc           -
  /        ,SECONDARY-ALLOCATION = sec-alloc ) )
  

• FGG on PRIVATE DISK

  /CREATE-FILE-GENERATION                             -
  /   GENERATION-NAME = fgg-name(*gen)                -
  /  ,SUPPORT = *PRIVATE-DISK(                        -
  /      VOLUME = volume                              -
  /     ,DEVICE-TYPE = device                         -
  /     ,SPACE = RELATIVE(                            -
  /         PRIMARY-ALLOCATION = prim-alloc           -
  /        ,SECONDARY-ALLOCATION = sec-alloc ) )
  

Meaning of parameters:

fgg-name               Name of the file generation group transferred to openUTM

gen                        Generation now to be opened

PUBLIC-DISK or PRIVATE-DISK

Specifies whether the file generation is to be created on public disk or private disk. openUTM takes this information from the catalog entry of the transferred SYSLOG-FGG.

VOLUME=volume, DEVICE=device

Volume identifier and device type of the disk on which the FGG is to be created.

PRIMARY-ALLOCATION=prim-alloc, SECONDARY-ALLOCATION=sec-alloc

Size of the initial allocation of storage space or the size of the storage space expansion.

If openUTM creates all generations of the FGG automatically, openUTM sets 192 PAM pages for both parameters. If openUTM has already opened an existing file generation of this FGG (one you created yourself) before creating the file generation, the values in the existing file generation for primary and secondary allocation are transferred by openUTM when creating subsequent file generations.

Creating the file generation yourself

If you want to define the values for primary and secondary allocation yourself for all file generations of the SYSLOG-FGG, you must create at least one file generation with the desired storage space specifications and transfer this file generation to openUTM as the first SYSLOG file. All subsequent file generations are then automatically created by openUTM with the specified values for primary and secondary allocation.

You can create the file generation using the following BS2000 command:

/CREATE-FILE-GENERATION                     -
/   GENERATION-NAME = filebase.SLOG(*1)      -
/  ,SUPPORT = *PUBLIC-DISC(                 -
/      SPACE = RELATIVE(                    -
/         PRIMARY-ALLOCATION = prim-alloc    -
/        ,SECONDARY-ALLOCATION = sec-alloc ) )

If the FGG is located on a private disk, you must also create the file generation on private disk.

Transferring the file generation to openUTM

You then transfer this file generation to openUTM as the first SYSLOG file. This can be done using the link name SYSLOG or by specifying the FGG base (see "File generation group SYSLOG-FGG").

If you work with the second method, then you must make sure that openUTM has not changed the base. If the FGG base is within the valid range of the FGG and you do not set the base to another generation before the next application start, then openUTM also begins with the same (base) file generation as the first SYSLOG file for the next application start.

The information from the previous application run may then be lost. Moreover, regardless of what you specified for OVERFLOW-OPTION when creating the FGG, only the n most recent file generations are retained (n=MAXIMUM in CREATE-FILE-GROUP). Please note section "Retaining SYSLOG generations".

 

To ensure that openUTM begins with the next generation as the first SYSLOG after one application ends and another starts, you should carry out the following steps before each start.

1. Set the base to the last FGG generation written (LAST-GEN):

   /MODIFY-FILE-GROUP-ATTRIBUTES                             -
   /   GROUP-NAME = filebase.SLOG                            -
   /  ,GENERATION-PARAMETER = *GENERATION-PARAMETER(         -
   /      BASE-NUMBER = RELATIVE-TO-LAST-GEN( 0 ) )
   

2. Create the next file generation:

   /CREATE-FILE-GENERATION                                   -
   /   GENERATION-NAME = filebase.SLOG(+1)                   -
   /   ......
   

3. Set the base to the file generation just created:

   /MODIFY-FILE-GROUP-ATTRIBUTES                             -
   /   GROUP-NAME = filebase.SLOG                            -
   /  ,GENERATION-PARAMETER = *GENERATION-PARAMETER(         -
   /      BASE-NUMBER = *RELATIVE-TO-LAST-GEN( 0 ) )
   

   You can only enter this command sequence once for each application start, not for each started UTM task.