Backup of one drive complete 100% but after that it remain in running state for longer time

We have netbackup master server version 7.5.0.4 which taking backup of client server having netbackup client version 7.1.

while taking backup of same client its one drive backup completed succesfully but for another drive backup complete 100% then it remain in running state for longer time. It does not complete.

Please help on this.