Automated Rollback

Automatic rollback processing involves:

• Transferring resources from the DATAMOVE machine back to the user
• Releasing any obtained, but unused, extents.
• Removing locks on devices

There are three scenarios where this can be performed by DirMaint:

• Failure of AMDISK subcommand. Several commands create a WUCF where one of the first operations involves the subcommand AMDISK. If this command should fail, DirMaint is able to release any device locks obtained by this transaction.
• Failure of DATAMOVE COPY request. The WUCF created for a CMDISK request involves using an AMDISK subcommand to create a new extent, transferring the original extent to a DATAMOVE machine, and requesting that the DataMove machine COPY the information from the old extent to the new extent. The new extent is then returned to the user and the old extent is released. Should the COPY request fail, DirMaint is able to:
  • Transfer the old extent back to the user
  • Release the new extent
  • Release any device locks obtained by this transaction
• Failure of DATAMOVE format. The WUCF created for an AMDISK that requires formatting involves the allocation of a new extent on a DATAMOVE machine, formatting it and finally transferring it to the user. If the format should fail, DIRMAINT is able to:
  • Release the obtained extent
  • Release any locks obtained by this transaction
• Failure of old minidisk CLEANUP. The WUCF created for an AMDISK, CMDISK, or DMDISK that requires clean-up of an old minidisk being released. If the clean-up should fail, DIRMAINT is able to:
  • Transfer a new minidisk to user
  • Release the old extent
  • Release any locks obtained by this transaction.