How to determine if a Unitrends system is using dedupNT or dedupDB


This articles provides instruction on how to verify whether a system is using dedupNT or dedupDB


This articles provides instruction on how to verify whether a system is using dedupNT or dedupDB.

DedupNT and dedupDB are technologies used in Unitrends deduplication technology.  As backup is deduplicated, the duplicate blocks are tracking using hashes.  DedupNT and dedupDB provide two unique methods for maintaining the hash references.  DedupNT and dedupDB cannot be used simultaneously and the technology must be chosen at the time of implementation.  Once a backup is performed, the technology cannot be changes without data loss. 

DedupNT maintains a flat file database for tracking hashes which reference the blocks required to unhash a backup.

DedupDB tracks hashes with the Unitrends postgres database.


Example shows hashes stored in the Unitrends postgres database:

[[email protected] ~# psql -c "select * from bp.hash_values limit 1"
 hash_id | hash_type | hashed_length |                                                             hash_value                                                             |
 sis_offset  | compressed_length
  477339 | sha512    |       1048576 | \x8eba449c1278c912d6f9eef12a36f497127d679ba28de5c54a8be0146df61b6b4b18d70dfa4b2fef06258c003d1bf2893d20ad672425e809c46a8c0898fe8805 |
340093353984 |            155728
(1 row)

The example shows the flat file metadata database does not exist on this system.  This indicates that dedupNT is NOT being used.
[[email protected] ~]# ls -ralsth /usr/bp/data/hashMetadata
ls: cannot access /usr/bp/data/hashmetadata: No such file or directory

All systems running Unitrends software 9.2 or higher will list the "MetadataGeneration" in the master.ini.
[[email protected]_UEB ~]# grep MetadataGeneration /usr/bp/bpinit/master.ini

MetadataGeneration=0 indicates dedupDB is being used.

MetadataGeneration=1 indicates dedupNT is being used. 

Note:  If you see MetadataGeneration=1 AND there are hashes listed in database from the PSQL query from above, that this will indicate a failed NT to DB migration, you will need to contact support for the NT to DB migration process to be run manually.  

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