- Verifying software compatibility - Before upgrading it is imperative to verify existing software installed on or relying on the servers being upgraded are compatible with the new software. Check with software vendors for specific information including supported software versions. Wherever possible, virtual machines work easiest, install the new operating system and software in question on a test server to verify all modules work correctly prior to upgrading.
- Cost of new OS + possible user CAL’s – Pricing for Server 2012 R2 Standard edition is around $900 while the Datacenter edition is over $6,000. Enterprise edition is not available in Server 2012 R2).
- Potential hardware upgrades – The minimum RAM requirements for Server 2003 R2 Standard and Enterprise 32-bit is 256MB, 64-bit Standard is 512MB, and 64-bit Enterprise is 1GB. While the minimum RAM requirements listed by Microsoft for Windows Server 2012 R2 is 512MB, most are running between 4 and 8GB. Even Windows Server 2012 R2 Essentials lists 2GB of RAM as the minimum, 4GB for virtual machines, and recommends 16GB. Processor speed and quantity of processors should also be a consideration when using existing hardware versus choosing to upgrade.
- Backing up data before upgrading – Make sure to have a complete backup data set before attempting any upgrade, whether in-place or to a new OS instance.
- Time for actual upgrade process – Keep in mind Server 2012 R2 does not accept in-place upgrades from any server OS prior to Server 2008 R2 with SP1. This means servers running Server 2003 can be migrated to Server 2012 R2 on new hardware, or via an in-place upgrade from 2003 to 2008 then to 2012 on the existing hardware. Upgrading twice can be quite costly, not only due to the licensing, but also in the amount of time each process takes including updates and service packs required to upgrade to each new version. Using the existing hardware for an in-place upgrade should also be carefully considered based on new software minimum requirements and existing hardware specs.
- Testing after implementation – Be sure to verify all the data was migrated or is still in place, all share permissions, and any server applications for compatibility issues.
Regardless of how many servers need to be upgraded, there are many considerations to take into account first. Before any data is copied or migrated, research will be necessary to make the best choices. Upgrading before the end of support for security fixes is important but is also a process which can take months. Getting started now can make the difference in how smoothly, or not, the upgrade process goes.