DB2 - SQL2428N The BACKUP did not complete because one or more of the requested log files could not be retrieved.

Question: During an DB2 ONLINE BACKUP , a SQL2428N error appeared.

 The backup command was:

db2 backup db MYDB online use TSM include logs

#Error message:
#SQL2428N  The BACKUP did not complete because one or more of the requested log
#files could not be retrieved.

Answer :  The DB2 ONLINE backup requires log files that were active at the start of the BACKUP to the log file containing the Online Backup End Record.

If the ONLINE BACKUP is running for a long duration – the active log file at the start of the ONLINE BACUP may no longer be available .

Confirm all the relevant logs from the ONLINE BACKUP start are  in the archive location.