I felt the need to blog about this quickly as it’s a question that’s coming up very frequently on the TechNet forums as firms are looking to perform an in-place upgrade of Lync Server 2013 to Skype for Business Server 2015. Many have deployed Lync on Windows Server 2008 R2, and they’d like to move to Skype for Business Server on Windows 2012 R2. Many want this simply because they want a more recent operating system. Further confusion arises from the TechNet article found here: https://technet.microsoft.com/en-us/library/Dn951388.aspx. Many read that Windows 2008 R2 is not listed as a supported operating system and stop reading. There is a further note that says:
You may have noticed Windows Server 2008 R2 isn’t on this list. That’s because we recommend Windows Server 2012 R2 for all new servers to be used for SFB. You should only be using Windows Server 2008 R2 when you have existing servers with Lync Server 2013 already installed, and you’re intending to do an in-place upgrade of them.
If you fall into this category, in hopes that you find it in your research, this blog is simply here to say DON’T DO IT! If you want to move to Windows 2012 R2 as part of your upgrade, please build fresh servers and move your users and objects over. Not only is this a supported upgrade path, there’s less downtime and potentially less risk as you can test and pilot all features before moving objects. In-place upgrades of the OS are unsupported and have been well known to break Lync. If you want some more evidence beyond my random blog, some of the comments in Doug’s blog post (two pages of comments) are a fun read: