NetVault version 9.2
Check NetVault version of clients being backed up. If there are clients is running NetVault 10.* this is the cause of the database corruption.
As seen below NVDBU is backing up the backup indexes and then fails with “Database Media Manager has dropped connection”
Background 2015/03/02 09:34:14 1070 Media SDC-BACKUP Backup 136148: index file (D:\Program Files\Bakbone Software\Netvault Backup\db\MediaDatabase\Files\Backup\0002\13\d4), Backup Id (bda46ba3a5446acfcb0b00003414000000000000), 1 sessions, Plugin Id 1099000
Background 2015/03/02 09:34:14 1070 Media SDC-BACKUP Backup 136149: index file (D:\Program Files\Bakbone Software\Netvault Backup\db\MediaDatabase\Files\Backup\0002\13\d5), Backup Id (c714a7ac09c889cf5f4a00006010000000000000), 2 sessions, Plugin Id 1099000
Error 2015/03/02 09:34:16 1070 Data Plugin SDC-BACKUP Database Media Manager has dropped connection
Error 2015/03/02 09:34:16 1070 Data Plugin SDC-BACKUP Fatal error while backing up Media Manager - Aborting
NetVault does not support client with a higher version than the server. The reason for the problem is that the index data will be in different format in NetVault 10 than NetVault 9.2 as the database has changed from flat files database to PostGresSQL database.
Install NetVault 9.2 client on clients that were running NetVault 10.
Implament solution on KB below to repair the database.
https://support.quest.com/netvault-backup/kb/148398