OpenTP1 Version 7 Operation

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4.5.1 Creation and definition of checkpoint dump files

A checkpoint dump file consists of multiple (2 to 30) file groups. File groups are logical files. Normally, one physical file is assigned to one file group but two physical files can be assigned to one file group (duplication).

Organization of this subsection
(1) Creation
(2) To duplicate a physical file

(1) Creation

  1. Initialization of a physical file
    Before starting OpenTP1, create a physical file for a checkpoint dump file on the OpenTP1 file system, with the jnlinit command.
  2. Correspondence between a physical file and a logical file (file group)
    Associate the created physical file to the file group, with the jnladdpf definition command in the checkpoint dump service definition.

(2) To duplicate a physical file

When a checkpoint dump file is duplicated, even if full recovery using the system A file failed due to an error, full recovery can be performed using the file of the other system (system B).

  1. Initialization of a physical file
    Before starting OpenTP1, create two physical files (one for system A and the other for system B) on the OpenTP1 file system, with the jnlinit command.
    The physical files for system A or B must be created over several disks. If all the physical files of either system is created on a single disk when one-system operation is unavailable, error in the entire disk disables the system. The OpenTP1 system will go down, assuming that there is no file group available.
  2. Definition
    Do not forget to specify jnl_dual=Y in the checkpoint dump service definition. The correspondence between a file group and the created physical files (for systems A and B) is specified with the jnladdpf definition command.
    When a physical file is duplicated, one-system operation is available in case of an error. One-system operation can be enabled or disabled with the jnl_singleoperation operand in the checkpoint dump service definition.

For details of the checkpoint dump service definition, see the manual OpenTP1 System Definition.