Recovering Data Sets

After recovering a volume or data set, you might have to recover some individual data sets. The sequence of commands you use should depend on the existence of entries for the data set in the BCS, VVDS, and VTOC. Normally, you only have to restore the latest backup copy of the data set. In some circumstances, you should first delete the data set's catalog or VTOC entries before recovery.

The following table shows the possible relationships between entries in the BCS, VVDS, and VTOC for a single data set. The recovery procedures noted are further explained after the table.

BCS	VVDS	VTOC	Recovery Action
entry present	entry present	entry present	normal
entry present	entry present	entry missing	normal
entry present	entry missing	entry present	normal
entry present	entry missing	entry missing	normal
entry missing	entry present	entry present	clean up, then recover
entry missing	entry present	entry missing	clean up, then recover
entry missing	entry missing	entry present	clean up, then recover
entry missing	entry missing	entry missing	normal

Following is an explanation of the appropriate recovery procedures:

normal

In these cases, you do not need to perform special actions before recovering a data set. For VSAM data sets and objects, import an exported copy. For non-VSAM data sets, replace the data set with a backup copy.

clean up, then recover

In these cases, where there are VVDS or VTOC entries for a data set, but no BCS entry, first delete the VVDS or VTOC entries. Then recover the data set using the normal procedure.

If you do not first clean up the VVDS, importing a VSAM data set or restoring an SMS-managed data set may create duplicate VVDS records. This duplication may cause problems when you try to use the data set.

If there is only a DSCB for a VSAM data set, you cannot import the data set unless you scratch the DSCB. For an explanation of the procedure for deleting VVDS records and VTOC DSCBs, see Deleting VVDS Records and VTOC DSCBs.