Note: The number of bitmap areas affects the maximum possible number of pairs that can be created in the storage system. For details on the maximum possible number of pairs, see section The Maximum Number of Pairs.
Journal Processing
The URz journal data contains the primary data volume updates and the metadata information (associated control information), which enables the secondary storage system to maintain update consistency of the URz secondary data volumes. URz journal processing includes:
•Creating and storing journals at the primary storage system (see the next section),
•Copying journals to the secondary storage system
•Storing journals at the secondary storage system
•Selecting and restoring journals at the secondary storage system
•Types of journals
Journal Processing at the Primary Storage System
When a primary storage system performs an update
Metadata information will be attached to journal data (see Table
Table 2-3 Metadata Information
Type
Description
Journal type | Type of journal (e.g., |
|
|
LDEV No. (data) | The number of primary data volume that stores the original data |
|
|
Original data storing position | The primary data volume slot number, and the start and end of |
| number (data length) |
|
|
LDEV No. (journal) | The volume number of master journal volume that stores the journal data |
|
|
Journal data storing position | The slot number of master journal volume, and the start |
|
|
Journal sequence number | The sequence number that is assigned when the journal is obtained |
|
|
Timestamp | The time when the journal data is obtained |
|
|
Chapter 3 Preparing for Universal Replicator z/OS Operations |
