Backup large Exchange DAG

[tjallingk]

I’m working on an Veaam design to backup a larger Exchange environment:

• - 4 virtual Exchange 2013 servers running on 4 dedicated Hyper-V servers with local storage
  - a single DAG cluster, 3 copies per database (1 active, 2 passive), evenly deployed across all 4 DAG servers
  - per DAG server approximately 16TB storage
  - as there is no single server containing all passive copies, all VMs will have to be backed up by Veaam

I’m particularly worried about the following:

• 1) Synthetic full will build a new copy of the full backupfile, temporary requiring a least 16TB per job (only 1 VM) or 64TB (combining all 4 VMs).
  
  Will this complete in an acceptable timeframe?
  Especially when rehydration needs to be performed (due to dedup)?
  
  2) As each database has 2 extra (passive) copies, the backup will potentially contain 33% unique Exchange data (and 66% copies)
  
  Will Veaam deduplication efficiently reduce this footprint to 33%?
  Does this require combining all 4 VMs in a single job?
  Is Windows volume deduplication on the backup target storage a good/better alternative?
  
  3) There is an undocumented(?) setting that allows exclusion of backup copies, which is required to prevent triple backups of each database.
  
  Will this database exclusion prevent copying the corresponding storage blocks? E.g. will this effectively reduce the backup footprint to 33%?
  Currently it is not a viable option to have one VM contain (only passive) copies of all databases, as there is not enough local storage available on these servers.

Is Veaam a suitable solution in this environment/setup?

I would appreciate any comments or answers to my concerns!

[foggy]

1. Depends on the storage capabilities and what is an acceptable timeframe in your case, but it will not be fast indeed (a lot of random I/O).
2. Windows deduplication is more effective, since uses variable blocks of much smaller size. Here's more about Veeam inline dedupe.
3. If you mean database exclusions enabled with EnableDBExclusions registry value, then it doesn't exclude databases from the backup itself, but only from VSS processing.