Duplicate from disk to Deduplication storage extremely slow

I am currently running on BE2012 with SP1 a and the latest 5 hotfixes on a server comprised of 2 x quad core XEON E5606 with 24GB of RAM on Windows server 2008 R2 with the latest updates.

The storage configuration is composed of 8 2TB disks configured in RAID 10 and another DAS of 5 x 2TB disks in RAID 5. The first storage (RAID10) is for B2D and the second (RAID5) is for duplication on deduplicated storage.

The issue that I am having is the time it takes to duplicate a backup and not because of slow read/write performance but because of the time it takes to start copying.

I am backing up different virtual machines with GRT file level backup activated for file servers and GRT SQL and EXCHANGE for SQL and EXCHANGE servers all through vCENTER. The backup goes smoothly being able to backup a 1,5TB file server in under 8 hours including verification.

But when I start the duplication process to deduplication storage I can see it starts copying first only 80KB of data, then waits about 20 minutes and starts copying 44GB (the system vmdk I suppose), then waits a wopping 12 hours before it starts copying the rest of the data about 1,4TB. When it is really copying the data it does it at 2500MB/min rate. For example, I backup the 1.5TB file server, in under 8 hours and duplicate it to the dedupe storage in 1 Day and 13 hours = 37 hours.

In all this time of waiting I cannot see any major activity in ram consumption, CPU usage, Disk usage or network usage.

I have to mention that I have used the RAID 5 partition, as a test, for a B2D job to see if there is anything wrong with the storage, but it was fine and was able to backup with a rate of 3900MB/min.

The only problem that I see is these time gaps between actually data transfers.

Regards,

Vlad

LE: If I backup directly to the dedupe storage, I get roughly the same speed as a normal backup with the exception of the verification process which takes the same time as the backup.