5.3.17 Operands related to server status files
- 54) pd_sts_file_name_1 = "logical-file-name", "file-a-status-file-name", "file-b-status-file-name"
- : ...
- pd_sts_file_name_7 = "logical-file-name", "file-a-status-file-name", "file-b-status-file-name"
- Define server status files. Although the pd_sts_file_name_2 to 7 operands may be omitted, the pd_sts_file_name_1 operand cannot be omitted.
- "logical-file-name"
<identifier>((1-8 characters)) - Specifies the logical file name of a status file for the single server.
- When a command that manipulates the status file is to be executed, the logical file name defined here must be specified.
- "file-a-status-file-name"
<pathname>((up to 167 characters)) - Specifies the name of the File A status file as an absolute pathname.
- "file-b-status-file-name"
<pathname>((up to 167 characters)) - Specifies the name of the File B status file as an absolute pathname.
- Specification guidelines
- The files specified as File A and File B should be status files created with the pdstsinit command.
- If a file that has not been created with the pdstsinit command is specified, a virtual status file is created.
- If an error occurs in a status file, HiRDB swaps the status files. If no spare file is available for swapping, the unit terminates abnormally. For this reason, defining a large number of system files improves system reliability, but at the expense of increasing the amount of disk space that is required.
- The status files specified for File A and File B must have the same record length and capacity.
- Operand rules
- Up to seven instances of this operand may be specified.
- A status file has a dual structure consisting of File A and File B; both must be specified.
- Environment variables cannot be used for the absolute pathnames of the File A and File B file names.
- The same names cannot be specified for the logical file name, the File A file name, and the File B file name.
- HiRDB file system area names are not case sensitive, but HiRDB file names are case sensitive. For example, for C:\hirdb\sysfile\sts01, C:\hirdb\sysfile is not case sensitive, but sts01 is case sensitive.
- Notes
- When HiRDB is started normally, the primary file (the file that was the primary file when HiRDB was terminated) is inherited. However, if there is no current file that can be inherited, for example because all status files have been initialized, the first status file that was specified among those specified by the pd_sts_file_name_1 to 7 operands becomes the current file, and the remaining files become spare files if they can be opened. Any files that cannot be opened become reserved files.
- When HiRDB is restarted, the primary file (the file that was the primary file when HiRDB was terminated) is inherited.
- Using a virtual status file
- Specifying a virtual status file makes it possible to add a new status file while HiRDB is running.
- For example, if the number of spare files is reduced because of errors in status files, virtual status files can be converted into spare files. The procedure for converting virtual status files into spare files follows.
- Procedure
- Use the pdstsinit command to create a status file in a HiRDB file system area for system files.
- Use the pdstsopen command to open the status file.
- These operations can be performed while HiRDB is running; there is no need to stop HiRDB.
- Advantages and disadvantages
Defining a virtual status file reduces the amount of space required in the HiRDB file system area. However, a virtual status file cannot be added as a spare file if the HiRDB file system area for system files does not have sufficient space (sufficient space for adding the file), thus reducing system reliability.
When virtual status files are not defined, the amount of space required in the HiRDB file system area is increased. However, because a swap destination is guaranteed when a file error occurs, system reliability is increased.
- Notes
When virtual status files are defined, HiRDB determines that a status file error has occurred when the unit is started. For this reason, HiRDB cannot start if stop (default value) is specified for the pd_sts_initial_error operand. When virtual status files are defined, specify continue or excontinue for the pd_sts_initial_error operand. It is also necessary before starting HiRDB to specify the current file in the pd_sts_last_active_file operand.