You can use one journal to manage all the objects you are journaling. Or, you can set up several journals if groups of objects have different backup and recovery requirements. Every journal has a single attached receiver. All journal entries for all objects being managed by the journal are written to the same journal receiver.
When deciding how many journals to use and how to assign objects to journals, consider the following:
- Using one journal (and journal receiver) is the simplest method for managing both daily operations and recovery.
There is a limit of 10,000,000 objects that can
be journaled to a single journal.
- If using a single journal receiver causes a performance bottleneck, you can alleviate this by placing the journal receiver in a separate disk pool from the objects that you are journaling.
- To simplify recovery, assign objects that are used together in the same application to the same journal.
- If you are journaling database files, all the physical files underlying a logical file must be assigned to the same journal.
- Files opened under the same commitment definition within a job can be journaled to different journals. In commitment control, each journal is considered a local location.
- If your major applications have completely separate objects and backup schedules, separate journals for the applications may simplify operating procedures and recovery.
- If you journal different objects for different reasons; such as recovery, auditing, or transferring transactions to another system; you may want to separate these functions into separate journals. However, you can assign an object to only one journal.
- If the security of certain objects requires that you exclude their backup and recovery procedures from the procedures for other objects, assign them to a separate journal, if possible.
- If you have basic disk pools with libraries, all objects assigned to a journal must be in the same disk pool as the journal. The journal receiver may be in a different disk pool. If you place a journal in a disk pool without libraries (non library disk pool), objects being journaled must be in the system disk pool. The journal receiver may be in either the system disk pool or the non library disk pool with the journal. See Determine the type disk pool in which to place journal receivers for more information about the types of disk pools.
- If you have independent disk pools, they must be library capable in order to journal objects on them. You cannot journal objects on User-Defined File System (UDFS) independent disk pools.