Upgrading to Skype for Business Server 2015

Microsoft has finally released Skype for Business Server 2015, the successor to Lync Server 2013, with a host of new features and capabilities that will take Unified Communications to the next level for the millions of users already using Lync today. Having just attended Ignite2015 in Chicago 2 weeks ago, I am excited to be writing a series of blog articles on Skype4B over the coming months. Lets begin with this first one - Upgrading Lync Server 2013 to Skype for Business Server 2015 Standard Edition. This article will cover the pre-requisites, supported upgrade scenarios, as well as walking through the steps required to do an in-place upgrade of Lync Server 2013 standard edition server to Skype for Business Server 2015.

Supported In-Place Upgrade Topologies
Skype for Business Server allows an in-place upgrade from Lync Server 2013 only topology, not a mixed topology that has both Lync Server 2010 and 2013 servers. For these mix environments, any existing Lync 2010 servers must first be migrated to Lync Server 2013 and de-commissioned before performing an in-place migration to Skype for Business Server 2015. For Lync Server 2010 only environments, a side-by-side migration to Skype4B server is supported. The table below summarizes the supported upgrade topologies:

Its important to note that all Lync 2013 servers in a pool must be upgraded to Skype4B together, ie no partial upgrading of servers within a pool. So in order to upgrade to Skype4B server without any user downtime, we will need at least 2 Lync 2013 server pools with a single pool having enough capacity to handle workloads for all users. During the in-place upgrade, we move all users from one pool to the other, then upgrade the first pool to Skype4B, before moving the users back, and then repeat for the other pool. If pool pairing is configured for these 2 pools then it should remain as paired pools during the entire in-place upgrade process. We cannot invoke-CsPoolFailover during the in-place upgrade. In addition, we should first upgrade Front-End Pools before upgrading other pool types such as Edge Pools, Mediation Pools and P-Chat pools etc. 

Server Pre-requisites
Hardware requirements remain mostly the same for Lync 2013 and Skype4B 2015, so this means that no additional hardware such as CPU, memory etc.. should be required. On the software side, we do need to ensure that the latest CU5 or higher is installed for Lync Server 2013. Note that for a fresh install of Skype4B Server 2015, the only supported OS is Windows Server 2012 R2, however for an in-place upgrade, we can use the existing OS that Lync 2013 server is on, but the following hotfixes are needed depending on the OS:
- Windows Server 2012: KB 2858668
- Windows Server 2012 R2: KB 2982006
- Windows Server 2008 R2: KB 2533623

Sykpe4B Server 2015 Standard Edition needs at least SQL Server 2012 SP1 or higher so if the server was installed with Lync 2013 server, most likely the version is SQL Server 2012 which means it needs to be updated first. To download and install SQL Server 2012 SP1, download the SQLEXPR_x64_ENU.exe from http://www.microsoft.com/en-us/download/details.aspx?id=35579. Then launch the exe and select the "add features..." option and follow the wizard to perform the update:

Note that the update has be done 3 times, once for each of the 3 databases RTC, RTCLOCAL and LYNCLOCAL:

Install Admin Tools on a separate server
We need the new Skype4B 2015 Server Topology Builder to upgrade and publish the topology. Since this cannot be installed on the existing Lync 2013 server, we need to run the Skype for Business Server 2015 setup.exe on a server that does not have any Lync 2013 components installed. At the setup screen choose to "Install Administrative Tools" and once complete run the new Skype4B Topology Builder. Choose to download the Topology from existing deployment and save it. Expand the Lync Server 2013 node to reveal the existing Standard Edition Front End Server. Then right click on it and select "Upgrade to Skype for Business Server 2015":

Once you click "Yes" to confirm the upgrade, the Standard Edition server will immediately be moved to the Skype for Business Server 2015 container and will no longer appear under Lync Server 2013. Note that we have no archiving or monitoring store associated with this front end server. Next publish the topology and when completed click Finish to close the wizard.

Upgrade the Lync 2013 Standard Edition Server
At this point the software on the Lync 2013 SE server must be upgraded but the services must first be stopped by running the Disable-CsComputer -Scorch cmdlet:

Next, we run Setup.exe from \Setup\amd64 on the Skype for Business Server 2015 installation media and allow it to install the VC++ redist components. On the launch window select "Do not check for updates" and accept the license agreement to continue. After verifying for upgrade readiness, the setup will install any missing pre-requisites and prompt for a restart if required. As shown below, the hotfix KB2858668 was required for Windows Server 2012: 

The rest of the upgrade process takes about 25-30 minutes depending on the server hardware but we can see the progress of the upgrade and the final completion shown below

The final step in the upgrade process is to start the pool using the powershell cmdlet Start-CsPool. After a few minutes the cmdlet should complete and a quick check of the services should show all Skype for Business Server services started and running:

We can launch the new Skype for Business Server 2015 Control Panel to administer settings for the new server:

At this stage we should login to a Skype for Business 2015 client and make sure all services are working properly. This concludes the Skype for Business Server 2015 in-place upgrade walkthrough.