Thanks to Remco, Paul, Daniel, Steve, Bill and Ray for your input.

Remco,

As a backup "service provider" I don't get a lot of input into the designs,
I'm expected to just take whatever is thrown at me and back it up. This
particular customer has got the "VMware Religion" and is virtualizing
everything, seemingly without considering whether the box in question is a
good fit for virtualization.  I could start to rant at this point but I'll
spare myself the embarrassment and you the noise.

The contract specifies a monthly backup.  Images are ok but for a really
large filespace you need a big chunk of disk to do the restore and it takes
hours just to get one or two files back.  Monthly incrementals are a much
better option IMHO, provided that they can be done.

I'd expect a <1% daily change rate on this disk, but at 10 Million files
that is still 100,000 objects a day. If they are like most word/excel docs,
they will be changed a number of times in a short period then get left
forever, and the deltas get smaller and smaller. I might try subfile and
see how it performs.  We can always turn it off later.  

Daniel,

Thanks for the Fastback idea.  I'm still awaiting recovery point and
recovery time objectives for this cluster, and if they are too stringent
will consider Fastback.  Will Fastback's VSS usage co-exist with other VSS
usage? I'm thinking of my monthly incremental here. There is also the
problem of needing more disk for the fastback backing store.

Steve, 

I didn't realize the implication that raw disks can't be imaged by VCB
backups.  But raw disks can be imaged by the BA client, and use VSS for
snapshots, so the failover problem solves itself.

Bill

If I can get hold of the architect I will ask about VDR and VMware failover
and why he made those choices.  VDR has size limitations as I understand
it, and that may be the issue, plus needing more backing store.  I'm also
not sure that VMware failover is free, or maybe they are just implementing
a tried and proven solution.

Ray

Along with the VMware religion goes consolidation frenzy :)  they already
have some sort of distributed file space, and obviously there are problems
with that hence the move to one single point-of-failure.  Good point
though.  


I'm much obliged to you all -- still need a script to
snapshot/mount/backup/unmount/delete-shapshot on Win 2k8

Thanks

Steve.

Steven Harris 
TSM Admin
Paraparaumu, New Zealand.