Hah! Partial success so far. My Firewire backup finished (surprisingly quickly) and it all looked good. So I went to restore some test files. While the Time Machine mounted the Drobo correctly it would not let me restore. How wierd is that?!? I could enter the Time Machine, but it wouldn’t mount the sparsebundle via Firewire.
Wierd eh? It will backup but not let me restore …
So I unmounted the Drobo and reconnected via USB to the Airport Extreme. And guess what? It worked! I was able to restore a larger file and a few thousand smaller files correctly.
The fact that the Drobo couldn’t access the sparsebundle while it was directly attached via Firewire concerns me, but I’m not going to obsess about it yet
I’m in the process of adding more data to the Drobo and we’ll see if it continues to work OK. I’ll need to fiddle with it for a few weeks before I make a decision on this product’s interoperability with Time Machine, but I can’t see it being a problem now (hope I haven’t spoken to soon).
In summary here’s what I did:
Created a 2 TB partition on the Drobo using the Dashboard on my Macbook (HFS+ File system).
Creates a sparsebundle image on my Mabook’s desktop using hdiutils:
sudo hdiutil create -size 500g -type SPARSEBUNDLE -nospotlight -volname “My Backup” -fs “Case-sensitive Journaled HFS+” -verbose ~/Desktop/MyMachine_##########.sparsebundle
where ###… is en0’s mac address. Variations of this script are everywhere.
Copied that sparsebundle file to the Drobo.
With the Drobo directly attached via Firewire initiate a Time Machine backup
After the backup is complete eject the Drobo and attach it to the Airport Extreme.
Reselect the backup target in Time Machine.
There’s a lot of seemingly unnecessary weirdness with apple’s fancy rsync, but if this does end up working OK I have every confidence the Drobo will work as advertised.
I think the initial problem was relying on the AE to create the initial sparsebundle and then perhaps having too much data traversing the wimpy AE’s USB port. Perhaps that caused the AE to shutdown the port and the Drobo then reset itself?