Concurrent image copy recovery
A concurrent image copy is fuzzy
because while IMS makes the image copy of the database, IMS might also be updating the database
at the same time.
For example, IMS might could update the database:
- Before the start of the concurrent image copy, and IMS might not have written those updates to the DBDS yet
- While the concurrent image copy is being taken
After restoring the data set from the concurrent image copy, IMS applies changes which occurred
while the image copy was being taken from the log. Therefore, to recover
a DBDS that has fuzzy image copies, you might need to supply logs
to the recovery job which have time stamps that precede the start
of the concurrent image copy. The DBRC GENJCL.RECOV
command
generates JCL with the correct logs listed.
If you use the database recovery service to recover a DBDS that has fuzzy image copies, the database recovery service automatically processes all the necessary logs required for the recovery.