Hi,
So we have a 10k phone system. Six server CUCM cluster, HA CUC, HA UCCX, CER, Legacy PBX, monitoring tools, external CTI integrations, etc.
Project is to migrate all to 9.X+ on UCS B-series.
Currently running 7.1.5, on MCS7845H2 servers (4gig, 146HDD).
Maintenance windows are not great to say the least.
The organisation is not too keen on rapid upgrades given all the inter-connected systems and potential hickups.
I have read lots of CUCM ideas on recommended overnight direct upgrades to 9.X, but they seldom consider dependencies for other systems that need to be upgraded/tested at the same time.
Our last major upgrade was from 4.X to 7.X and we developed a migration plan to run both CUCM clusters side by side with inter-cluster trunks during the migration process.
I'll skip the details, but we reloaded the old cluster on new hardware, changed the host/ip, rehosted the licences and managed CSS / partitions so that phones were either visible in one cluster or the other.
All other systems were re-installed from scratch, rehosted and data migrated (CUC-COBRAS, UCCX-manual copy, ...). Old cluster was retired once all services were migrated to the new cluster.
Bottom line is that we had a smooth and controlled migration over a few weeks. More work, less risk.
I am looking for inputs on things that may not work this time given new licensing strategies and VMware version restrictions.
My current plan is to create a parallel UCS/9.X+ cluster this time again and to re-install other UC apps from scratch:
- Leave the current 7.1.5 cluster running as-is during migration, as well as other UC apps.
- DRS the 7.1.5 CUCM cluster
- DRS restore on temp MCS (using same IP/hostname in standalone vlan. Maybe fake DNS, NTP and default gateway)
- My hope is to "DRS restore" only the Pub to save on temp MCS servers
- Change temp MCS Pub IP/hostname
- Rehost licence on temp MCS still running 7.1.5
- Put back temp MCS on production network
- Upgrade temp MCS to 9.X+, with ELM licensing process
- DRS from MCS to newly installed UCS B-series with 9.X+
- Rehost licence for UCS
- Create new UCS TFTP server and UCS Subs from scratch to recreate the production cluster on UCS
- Create inter-cluster trunk between old 7.1.5 cluster and new cluster 9.X+
- Add new CUC, UCCX, CER, ... on UCS.
- Use same migration plan as the last time for our 4.X to 7.X controlled migration of users and services.
- Yes, we have two mostly identical clusters running side by side for a few weeks... this worked great the last time.
More work, but less chance of rolling back at 3:00 in the morning...
Let me know if you have reasons to think this will not work, or if there is an easier path to controlled migration of all our telephony systems.
Your comments are welcome !
Thanks,
Eric
