So I have had a thread about the best way to backup to NAS using Veeam in terms of performance, but am also trying to figure out the best way to Backup now - i.e. what backup strategy to use.
My requirements are:
1. Backup to NAS (of course) - this provides cheaper storage than backing up to SAN. Also we do not use a physical Veeam B&R server, so no possibility of using Direct SAN mode here either
2. Backups need to exist on local site and remote site in case the QNAP NAS on either side went down and we needed a backup.
3. Try and save as much storage space on NAS (i.e. use incrementals/reverse incrementals)
4. Try and save as much bandwidth as possible (i.e. replication should not have to copy the full VBKs over the 1GBit link between data centres every day, only the stuff that changes - like the VIB or VRB files).
Here is a basic diagram of my infrastructure I did using the (awesome) free Veeam stencils for Visio


The two data centres are completely remote sites, but have a 1GBit connection via Fibre. Backups run at night (mostly) and one of the requirements listed above is to have these replicated on the other side. Basically, there will be two replication jobs configured - one on the QNAP NAS at Primary DC and one at the QNAP NAS at the Secondary DC. Here is where I have two choices:
a) Backup VMs running at Primary DC to QNAP NAS at Primary DC. Replicate these the next morning to Secondary DC using rsync job. Do the same, but in reverse for the VMs running at the Secondary DC.
b) Backup VMs running at Primary DC to QNAP NAS at Secondary DC. Replicate these back to the Primary DC QNAP NAS the next morning using rsync job. Do reverse for VMs running at the Secondary DC.
My ideas so far have been (All of these use either Network backup mode or VA backup mode) :
1. Backup VMs running at relevant Data Centre. Replicate using rsync the next morning to other data centre QNAP NAS storage (scenario (a) or (b) above). Use Reverse Incremental mode and somehow set up hardlinks so the names don't change and I don't end up with tons of full VBK files replicating across and wasting space and bandwidth.
This would be nice, but its messy - it will take a fair amount of effort to set up hard links and maintain all of this. We have a lot of jobs, so there will be a lot to configure, and even more configuration needed everytime we add a new Veeam backup job.
2. Backup VMs running at relevant Data Centre. Replicate using rsync the next morning to other data centre QNAP NAS storage (scenario (a) or (b) above). Use Normal Incremental mode with a weekly full backup scheduled in. This way full VBK will be replicated to other data centre site once a week, and incrementals will be provide quicker replication every other day.
This option would probably work fine, but has disadvantages such as jobs are incremental, and having a corrupted incremental job file (VIB) in-between could mean losing the latest backup should we need to restore.
So, what do you guys think? Any advice, improvements on the above, or better ideas? I am getting fairly desperate as currently used backup storage on each site's SANs is running low, and I would like to get existing jobs moved over to the NAS devices

Cheers