Backup fails with error “Attempt to save a stream with missing segments” in binary log.
Checking the internal data of this error it can be seen that we are issuing a PostgreSQL database call then we see error “New stream is longer than coverage by backup segments”. This is shown in binary log extract below.
Binary log extract:
Error 2018/10/31 10:41:44 2455 Media server_backup Attempt to save a stream with missing segments
6 DBCONNCT:02316 25 0 104144.008327 (1,2/2){SELECT * FROM medmgruncommitedsegment WHERE sessionid = $1 AND sessionphase = $2 order by streamid,segoffset ASC}
4 DBWRKFLW:02316 2 0 104144.008691 Query returned 1 rows
2 MEDDBCHK:02316 1829 0 104144.008814 Found 1 segments
1 MEDDBCHK:02316 12499 0 104144.008821 Check coverage of new stream '864cd73d0b74b6c9b5480000882e000001000000', id 1, length 32243712, encrypted='FALSE'
2 MEDDBCHK:02316 12307 0 104144.008827 This segment '864cd73d51e0b6c929000000882e000007000000', offset 0, length 32243712
2 MEDDBCHK:02316 12308 0 104144.008833 Segment tStreamId '864cd73d0b74b6c9b5480000882e000001000000', offset 0, length 32243712
2 MEDDBCHK:02316 11452 0 104144.008839 Check segment '864cd73d51e0b6c929000000882e000007000000', offset 0, length 32243712
2 MEDDBCHK:02316 11453 0 104144.008840 Accumulative offset 0
2 MEDDBCHK:02316 2674 0 104144.008842 Have coverage
1 MEDDBCHK:02316 12499 0 104144.008848 Check coverage of new stream '864cd73d2a8bb6c91f1f0000882e000003000000', id 2, length 131071, encrypted='FALSE'
2 MEDDBCHK:02316 12307 0 104144.008853 This segment '864cd73d51e0b6c929000000882e000007000000', offset 0, length 32243712
2 MEDDBCHK:02316 12308 0 104144.008858 Segment tStreamId '864cd73d0b74b6c9b5480000882e000001000000', offset 0, length 32243712
0 MEDDBCHK:02316 1827 0 104144.008860 New stream is longer than coverage by backup segments
Possible media database corruption for problem backup.
OPTION 1
1/ create a brand new full and incremental backup for the client which NetVault is backing up from. Use a new selection set but keep other backup sets.
2/ Run the full and run the incremental shortly after.
OPTION 2
If keeping the original backup is desirable we could attempt to repair the database using the following steps but this procedure is not a guaranteed fix.
1/ run NetVault database backup with no other backups running so we have copy of the current database
2/ stop NetVault services after database backup completes making sure no new backups run after database backup completes
3/ open CMD as administrator and use nvmeddbcheck command. Save the output to file and force to repair the database. See following KB for this:
https://support.quest.com/netvault-backup/kb/79428/how-to-use-the-nvmeddbcheck-utility-to-check-and-compact-the-media-database-video
4/ on completion, run the original backup, both full and incremental to verify if we have repaired the problem.
If problem is not resolved using this procedure then please log a case with our Support team
