> If you remove any aggregate on the disks, zero them and remove ownership on the 8.1.x filer then you should be able to use them on a 7.3.x filer.

I'd try that except this older filer is headed out the door and the other filer is staying on 8.1 (and is also headed out the door).

> And indeed very annoying/frustrating that there is no way around this.

(sigh) NetApp. There's always something new to raise the eyebrow. Apparently the disk relabeling does actually work between certain DOT releases. I guess 8.1.3 to 7.3.7 is too much.