Test your Citrix muscle…

True or False: Always use Provisioning Services

Answer: False

There has always been this aura around Machine Creation Services in that it could not hold a candle to Provisioning Services; that you would be completely insane to implement this feature in any but the simplest/smallest deployments.

How did we get to this myth? Back in March of 2011 I blogged about deciding between MCS and PVS. I wanted to help people decide between using Provisioning Services and the newly released Machine Creation Services. Back in 2011, MCS an alternative to PVS in that MCS was easy to setup, but had some limitations when compared to PVS. My blog and decision tree were used to help steer people into the PVS route except for the use cases where MCS made sense.

Two and a half years passed and over that time, MCS has grown up. Unfortunately, I got very busy and didn’t keep this decision matrix updated. I blame the XenDesktop product group. How dare they improve our products. Don’t they know this causes me more work? :)

It’s time to make some updates based on improvements of XenDesktop 7 (and these improvements aren’t just on the MCS side but also on the PVS side as well).

So let’s break it down:

  • Hosted VDI desktops only: MCS in XenDesktop 7 now supports XenApp hosts. This is really cool, and am very happy about this improvement as so many organizations understand that XA plays a huge part in any successful VDI project.
  • Dedicated Desktops: Before PVD, I was no fan of doing dedicated VDI desktops with PVS. With PVD, PVS dedicated desktops is now much more feasible, like it always was with MCS
  • Boot/Logon Storms: PVS, if configured correctly, would cache many of the reads into system memory, helping to reduce the Read IOPS. Hypervisors have improved over the past 2 years to help us with the large number of Read disk operations. This helps lessen the impact of the boot/logon storms when using MCS.
  • SAN Required: MCS doesn’t require a SAN. This is a long-held misconception mostly because MCS was so new and unknown. I’ve seen many go with local storage when using MCS.
  • Change control: This one was just a little confusing and I was never happy with how I dealt with it. Basically, it used to be difficult to manage PVS images and the entire process behind it. PVS has improved over the years to make this much easier and streamlined with automated tools.

That’s much better. But wait, there is still one item not crossed out yet.

  • Blade PCs: Yes, MCS only works on top of a hypervisor. So if you go with a blade PC or a physical target, you still use PVS. This is a great option for labs and classrooms.

So what is one supposed to use if they don’t need blade PCs or physical targets? My thoughts…

  • If you already use PVS, then keep using PVS
  • If you are new and you have enough storage throughput to support slightly higher IOPS requirements from MCS, use MCS due to simplicity

In a future blog, we will dive a little deeper into the technical impact both of these options will have including IOPS, storage space and resource requirements.

NOTE: This blog is about XenDesktop 7 and MCS/PVS.  Older and newer version have different features/functionality. 

Daniel – Lead Architect