Upgrading workstations used for management

The Exchange 2013 Management Shell (EMS) can run on either Windows 7 SP1 (x64) or Windows 8–based workstations. Unlike Exchange 2010, workstations running Vista SP2 (x64) are not supported, so you might need to upgrade workstations you want to use for management. However, remember that the Exchange Administration Center (EAC) is now browser-based and capable of running on a wide range of platforms, including Windows Surface RT devices, Apple iPads, and Android tablets. These devices suffice for the vast majority of administrative activities performed against Exchange 2013 servers, and you’ll only need a more capable workstation if you want to run EMS either interactively or to execute a shell script.

2. Using virtualization

Virtualized platforms have made enormous strides in capability, performance, and robustness over the past five years, yet Exchange has not always been desirable in this sphere. In the past, two major factors were at play that caused Exchange to maintain almost a hands-off approach when virtualized servers were contemplated. First, Microsoft did not have a competitive hypervisor, and VMware dominated the market. This is not a technical reason for not supporting virtualization, but it is certainly a good commercial reason for going slowly, especially because Microsoft knew that Hyper-V, its own hypervisor, was coming. Second, Exchange 2003 and Exchange 2007 exert heavy demands on storage subsystems, and users doubted that Exchange servers could run well on virtualized servers when put under strain.

VMware took the opposite attitude of Microsoft and went about the business of proving that it was quite possible to run Exchange 2007 (in particular) on virtual servers. Microsoft didn’t support customers who took the advice of VMware that virtual servers were a viable platform, and customers who used VMware were forced to duplicate any problems on a production server before they could look for support. Overall, a highly unsatisfactory situation existed.

The advent of Hyper-V changed the situation because Microsoft could not say that virtual servers worked on one hypervisor but not another. In any case, after a technology company moves into an area, it makes sense for the different parts of the company to expand and embrace the new area, which is what happened when Microsoft development groups began to work with virtual servers and establish just how well (or not) their products functioned. In the case of Exchange, formal support for VMware came from Exchange 2007 SP1 onward with some notable caveats concerning clustered mailbox servers running continuous cluster replication or standby cluster replication, the predecessors of today’s DAG. The potential clash between the high-availability features enabled through virtual servers and those Exchange uses are still problematic. Virtual servers don’t know how DAGs work, and DAGs don’t know when their member servers are virtual machines, leading to strong guidance from Microsoft to let the application-level high-availability software do its work rather than depending on the hypervisor. Therefore, don’t let the virtual platform move DAG member servers around, especially between clustered root servers; you might end up with unpredictable and unsupportable situations. Developments and improvements will come in this area over time, and it’s certainly a situation worth watching.

The second issue concerning the demands Exchange placed on storage subsystems was largely addressed by the major improvements in I/O performance in Exchange 2010 with even better performance coming in Exchange 2013. The work done to enable Exchange to run on low-cost disks delivered considerable benefits for virtual servers, so virtual platforms have become very popular in the Exchange community.

Even though the latest versions of VMware and Hyper-V are very capable hypervisors, many still prefer to use physical computers for Exchange mailbox servers. Virtual servers are good choices for CAS servers and Edge servers because these servers have little or no data on them that cannot be recovered easily in case of failure. Virtual servers can also serve as excellent platforms for other parts of the Windows infrastructure, such as print servers or even domain controllers, as long as the core of Active Directory is running on some highly available physical computers.

My attitude toward mailbox servers is very possibly rooted in years of experience with physical computers and the consequences of hardware failure for the core of an email system. The choice to deploy Exchange on physical or virtual machines will be guided by the architectural choices a company makes and the knowledge of the IT administrators. Both Microsoft and VMware publish interesting and valuable documents to provide guidance about how best to deploy applications such as Exchange 2013 on virtual servers. Virtualization is a fast-moving area of technology; it is wise to track developments and be open to advances in that technology.