Library user disk pools

 

Library user disk pools contain libraries and user-defined file systems (UDFS). Library user disk pool steps are easier to recover than nonlibrary user disk pools.

• Do not create system or product libraries (libraries that begin with a Q or #) or folders (folders that begin with a Q) in a user disk pool. Do not restore any of these libraries or folders to a user disk pool. Doing so can cause unpredictable results.

• Library disk pools may contain both libraries and document library objects. The document library for a user disk pool is called QDOCnnnn, where nnnn is the number of the disk pool.

• Journals and objects that are being journaled must be in the same disk pool. Place the journal receivers in a different disk pool. This protects against the loss of both the objects and the receivers if a disk media failure occurs.

  In order to begin journaling, the journal (object type *JRN) and the object to be journaled must be in the same disk pool. Use the following commands to start journaling:

  • Start Journal Physical File (STRJRNPF) command for physical files

  • Start Journal Access Path (STRJRNAP) command for access paths

  • Start Journal (STRJRN) command for integrated file system objects

  • Start Journal Object (STRJRNOBJ) command for other object types

  Journaling cannot be started again for an object that is saved and then restored to a different disk pool that does not contain the journal. The journal and the object must be in the same disk pool for journaling to be automatically started again for the object.

• No database network can cross disk pool boundaries. You cannot create a file in one disk pool that depends on a file in a different disk pool. All based-on physical files for a logical file must be in the same disk pool as the logical file. The system builds access paths only for database files in the same disk pool as the based-on physical file (temporary queries are not limited). Access paths are never shared by files in different disk pools. Record formats are not shared between different disk pools. Instead, a format request is ignored and a new record format is created.

• You can place an SQL collection in a user disk pool. You specify the destination disk pool when you create the collection.

• If the library user disk pool does not contain any database files, set the destination access path recovery time for the disk pool to *NONE. This might be true, for example, if the library user disk pool contains only libraries for journal receivers. If you set the access path recovery time to *NONE, this prevents the system from doing unnecessary work for that disk pool. System-managed access-path protection describes how to set access path recovery times.

 

Parent topic:

Planning for disk pools

Related information
System-managed access-path protection