Question about replication between two d2d

[gael_38]

Hello,
I use Backupexec 2012 sp2 with two D2D that are replicated. The first source is an HP StoreOnce D2D 4210 FC and the second target is a HP StorageWorks D2D D2D4106fc.
Replication for the moment on 48 slot replicated with the vtl 800 GB (LTO5).
I have a few questions about the replication system between D2D and wanted to know if by any chance if you have the answers.
From my testing backups, each replication, the replication job covers all of the cartridge and not on last backup concerned.
For example, on a cartridge or I will add 20GB of backup while already contained 700, synchronization will focus on the entire cartridge is 720 GB
The data are transited between two D2D it concern you the 720GB or the actual size taken on the disk of the source D2D?
I feel that replication is done on the 720 GB and not on the size actually used on the disk and deduplication is once again replicated data. Besides, I have a difference of ratio and actual space occupied for the same stored data.
On the other hand, is there a way that replication is limited to data from the last backup?

[Emil Velez_2]

1. If you are replicating cartridges in your backup program you should make your tapes non appendable. This way a new backup job even incrimental is written to a new cartridge and only that cartridge is replicated. As you have figured out the whole cartridge is replicated and if it changes it is re replicated.
2. Actually replication between devices is done thin.. Meaning it replicates the unique blocks and pointers. It integrates the unique blocks and pointers into the destination library deduplicaton store and all of the cartridges on the destination library.