The filesystem volume name for a Unidesk layer looks like this:
UDiskP<layerId>V0Rx – for instance UDiskP8F0018V0R3
“layerId” is an internal hexadecimal number identifying the layer, but you can get it from the machine name. Run HOSTNAME from the packaging machine, and it’ll be named something like CITRXAL8f0018. Strip off CITRXAL and render that hex number in caps and you have the LayerId. (It also shows up in a few logs and the registry, but HOSTNAME is a cheap way to get it.) What I can’t tell you is the revision number – the “x” in the “Rx” at the end of the name. That’s a sequence number that increases every time you attempt to add a version to a layer, not every time you succeed. So this might be your second revision, but your tenth attempt, and this would be R10 instead of R2. Nowhere in the packaging machine is the revision number stored. Nowhere in the ELM that you can see is the revision number displayed.
However, it turns out that we don’t actually care about the R number. We just require it to be there. So pick one. The layer ID, however, must be correct. If you substitute an incorrect layer ID, Finalize will simply fail further on.