Vishal,

I manage a similar configuration, but with NetWorker 7.6.4 and a DD860 and 
DDBoost. The NetWorker server involved here runs on a 64-bit Linux host, not 
Windows 2008. I also stagger full backups during the week in order to minimize 
network bandwidth and tape drive utilization. In this configuration, two LTO-5 
drives are used in a Spectralogic t50e tape library with hardware tape 
encryption enabled. I use group cloning to copy the backed up data from the DD 
system to LTO-5 tape. 

I also do not see any advantage of using a DD system in a VTL configuration, so 
I don't do that.

We have done quite a few successful recovers, for real and for testing 
purposes, from DD and magnetic tape. The only thing to be aware of is that if 
you do a recover while a tape is mounted, the recovered data will be pulled off 
tape, not DD. To ensure the recovered data is restored from DD, the tape cannot 
be mounted. This behavior might have changed in the 8.x NetWorker stream 
though, but it is not a big deal once you are aware of it. 

Another thing to be aware of is that you can conceivably have a group run 
longer than 24 hours because it will not complete until the tape cloning 
operation is finished. Also, if the group fails due to a failure of a single 
backup client issue, the cloning to tape will be skipped. Fortunately, that 
problem rarely happens and NetWorker 8.1 might behave differently.

On Aug 2, 2013, at 11:35 AM, Vishal Gupta <vvishalgupta AT GMAIL DOT COM>
 wrote:

> Hi Guys,
> 
> Brainstorming various possible config. with the following; Your inputs are
> welcome please:
> 
> - NW 8.1 (WIN 2008)
> - DD 890
> - Daily incr (30TB)
> - Weekly full (140TB)
> 
> 
> Primary Plan:
> 
> The data will be backed up to DD (daily-incr; weekly-full) thru DDboost &
> then to tape thru cloning DAILY.
> 
> Queries:
> 
> 1. Is it an OK setup to go for wherein the data would go to DD thru DDboost
> & then to tape thru cloning? Any implications? performance issues? recovery
> issues?
> 
> 2. Shall I go for DD as a VTL instead of DDboost & then do the cloning to
> tape.
> 
> Please Note: Cloning has to be done on a daily basis for tape off-siting
> purposes.
> 
> 
> 
> ~Vishal Gupta