To use a DVD-RAM library device, you must take steps to avoid detection of false timeouts caused by the fact that the physical mounting operation (staging) takes a long time. Therefore, specify a value in the operands listed below that adds the time required for the mounting operation to the previous estimate:

• pd_lck_wait_timeout (lock-release wait time)

You create a HiRDB file system area in a normal file or character special file in a DVD-RAM library device.

Creating a HiRDB file system area in a normal file

A HiRDB file system area created in a DVD-RAM library device can be manipulated in the same manner as a HiRDB file system area created on a magnetic disk. However, when considering performance and availability, we do not recommend using such file system areas for system files (SYS), work files, or list RDAREAs (WORK).

Creating a HiRDB file system area in a character special file

If you create a HiRDB file system area in a character special file in a DVD-RAM library device, you must take into consideration the sector length of the DVD-RAM library device. When the sector length is 512 or 1,024 bytes, the HiRDB file system area can be manipulated in the same manner as a HiRDB file system area created in a character special file on a magnetic disk. However, when considering performance and reliability, we do not recommend using such file system areas for system files (SYS), work files, or list RDAREAs (WORK).

Notes

Note following points when the sector length is 2,048 or 4,096 bytes:

1. Only the files listed below can be created in a HiRDB file system area created using this procedure:
   - HiRDB files comprising RDAREAs (excluding list RDAREAs)
   - Backup files
   - Unload log files
   - Unload data files
   
2. Execute the pdfmkfs command, then use the -s option to specify the sector length. You cannot use the -k option to specify SYS, WORK, or SVR.
3. When you use the database initialization utility (pdinit command) to define an RDAREA, specify in the page operand (page length) in the utility control statement a value that is a multiple of the sector length.
4. When you use the database structure modification utility (pdmod command) to add, extend, or reinitialize an RDAREA, specify in the page operand (page length) in the utility control statement a value that is a multiple of the sector length.
   Hitachi cautions against omitting the page operand during reinitialization of an RDAREA. If the page length of the RDAREA before reinitialization is not a multiple of the sector length, the RDAREA cannot be reinitialized.
   
5. When you use the pdfrstr command to restore a HiRDB file, the record length of the HiRDB file to be restored must be a multiple of the sector length of the HiRDB file system area into which the file will be restored. The record length of a HiRDB file can be checked with the pdfls command.
6. When you use the database recovery utility (pdrstr command) to recover an RDAREA, the page length of the RDAREA to be recovered must be a multiple of the sector length of the HiRDB file system area. If the page length is not a multiple of the sector length, the RDAREA cannot be recovered. For example, if the medium that a HiRDB file system area is created on is being replaced because of a physical failure, check that the sector length of the HiRDB file system area on the new medium is the same as on the medium being replaced.

When you define an RDAREA on a DVD-RAM library device, use SCHEDULE as the RDAREA opening trigger attribute. If you use INITIAL (the default), all HiRDB files will be opened when HiRDB is restarted because RDAREA information resides in memory. When opening processes accumulate on a DVD-RAM library device, disk swapping might occur often and result in the HiRDB startup process timing out. By using the DEFER attribute, you can avoid accumulation of opening processes when HiRDB starts, but they will accumulate when HiRDB terminates normally.

Also, when you use a normal file with the INITIAL or DEFER attribute, reactivation will not be performed smoothly because fsck will be executed on all media HiRDB opens during the next OS startup if a power outage or restart occurred while HiRDB was still active.

RDAREA opening trigger attributes are not suitable for operations with DVD-RAM library devices, because the RDAREA opening trigger attribute is fixed to INITIAL for the master directory RDAREA, data directory RDAREA, data dictionary RDAREAs, data dictionary LOB RDAREAs, and registry RDAREA. You should create these RDAREAs on a magnetic disk.

To change the opening trigger attribute of RDAREAs to SCHEDULE, specify pd_rdarea_open_attribute_use=Y and take one of the following actions depending on the number of RDAREAs to be assigned the SCHEDULE attribute:

When changing many RDAREAs to the SCHEDULE attribute

Specify pd_rdarea_open_attribute=SCHEDULE. This specification makes all RDAREAs in the entire system valid except for the master directory RDAREAs, data directory RDAREAs, data dictionary RDAREAs, data dictionary LOB RDAREAs, and the registry RDAREA.

When changing a small number of RDAREAs to the SCHEDULE attribute

Define each such RDAREA by specifying it in a control statement of one of the following utilities:

• Specify SCHEDULE in the open attribute operand of the database initialization utility (pdinit command)
• Specify SCHEDULE in the open attribute operand of the database structure modification utility (the pdmod command)

Such a specification is valid only for the specified RDAREA. Also, when used in conjunction with specification of the pd_rdarea_open_attribute operand, the specification for the utility has the higher priority.

Reference note

Specification of an opening trigger attribute in this manner does not take effect immediately after the database structure modification utility is used to add an RDAREA because the opening trigger attribute starts out as INITIAL. To activate specification of the opening trigger attribute, you must restart HiRDB. The specified opening trigger becomes effective regardless of the startup mode.