VSAM files created through the DB2 database management software normally observe the naming convention of using DSNDBC as the second-level node of the data set name. CA Disk automatically detects these data sets and formats them in control interval images rather than logical record format.
A DB2 system consists of the following files:
LDS data sets that consist of a collection of tablespaces that contain information on objects defined to DB2. This catalog is where backup and reorg information (that is, image copy backups) is stored.
The bootstrap data set (BSDS) is a KSDS file used to keep track of the RBAs during startup and shutdown. This file is also used for recovery and restart operations.
A logging system that records all changes (that is, COMMITS) into an ESDS database.
One or more LDS files (data tables) that make up one or more DB2 Tables. Tables can be simple, partitioned, or segmented.
A set of pointers that reside in one or more physical LDS files (index tables). There are unique indexes that protect against two rows in a table having the same key value. Cluster indexes are used to determine how rows are divided between partitions and control the order in which table rows are stored.
CA Disk supports all of the files mentioned previously. CA Disk can be used to logically backup, restore, and move both system related (Log, Bootstrap, Catalog) and application related (Data and Index tablespace) files.
Even though CA Disk does not interface to the DB2 catalog, sites using DB2 release 2.2 and 2.3 can use CA Disk as a backup supplement to the DB2 IMAGE Copy Utility. For example, page level incremental backups can be made with DB2 IMAGE Copy and Tablespace level backups with CA Disk by using the SELECT TABLE= parameter.
CA Disk can be used to restore large or partitioned tables in the event of a DASD failure or data corruption instead of using IMAGE Copy backups.
DB2 release 3.1 has the ability to perform a Log-only recovery. This allows a DB2 table to be restored from a non-DB2 utility such as CA Disk. After CA Disk has restored the table; the user has the option to specify the starting log RBA from where to apply the log changes. The speed and flexibility of CA Disk over the DB2 utilities makes the restore of large tables both easier and faster. This, in turn, reduces the downtime for the application.
CA Disk has the ability to backup VSAM files that are in use by specifying sysparm VSALOSHRy. However, it is best to have the files backed up closed or in read-only status, or the DB2 system can be down altogether.
|
Copyright © 2015 CA Technologies.
All rights reserved.
|
|