So what did we learn?
I tested using the DMA tool on a dummy system in our attempt to see what could break during the process - and during the process I found no problems. Great! What we didn't really bank on was some issues with the installation of CM5 with the real customer's DMA file. The problem that occurred caused the CM installation to crash and at first we thought it was a problem relating to delete.CSV being present in the DMA tar file; but using the tar tool to remove it didn't solve the issue. It turned out to be a problem relating to the new 7937 Cisco phone, and a typo in one of the XML files. We got Cisco TAC on the case and their brilliant engineers got us to the install day.
After the DMA had completed we did find several other (small) problems but were easily sidestepped:
- It was impossible to delete some old device pools because the device defaults claimed they were assigned to the device pools- but they weren't...
- The Subscriber is having problems replicating databases even though the system health check says all is well.
- Various auto generated device profiles could not be deleted because they were assigned to phones that didn't exist.
Overall the whole process was very successful, but it took a while to complete and we came up against some problems which were definitely "show stoppers". DMA is a fantastic tool, but for all budding upgrades out there -plan, test, plan, test.