Our Oracle DBAs perform their own restores using our NB (8.2). One of them has been having a problem :
"Could someone please help me troubleshoot the error from the alert log?
I ran into this error while restoring XYZPRDB database from 2017 October backups on xyzdbdvh1 host.
Before the failed restore I had one successful restore.
ORA-19507: failed to retrieve sequential file, handle="xyzprdb_ONLINE_20170401_1800.p1.s224212.940198269", parms=""
ORA-27029: skgfrtrv: sbtrestore returned error
ORA-19511: Error received from media manager layer, error text:
Backup file <xyzprdb_ONLINE_20170401_1800.p1.s224212.940198269> not found in NetBackup catalo
failover to previous backup
It means Orcale requestd backup xyzprdb_ONLINE_20170401_1800.p1.s224212.940198269 but Netbackup answered it didn't know about that backup.
My recommendation is to run a RMAN "cross check" to sync the RMAN recover catalog with the Netbackup catalog. Please consult your DBA.
Once RMAN and Netbackup agree what backups exist, RMAN may choose to restore a different backup.
Also there is a general help to find in:
Best Practice for maintaining a consistent backup catalog between Oracle RMAN and NetBackup