AHV vs Vmware, AOS 5.0 edition

 

UPDATE: This information is based on older AOS 5.0 version , for comparison between AOS 5.5 and Vsphere, plese read updated version

Few months ago I compared Vmware against Acropolis Hypervisor. At that time I listed ten use cases or features where Vmware was better or the only option as Hypervisor in Nutanix environment.

Now that Nutanix is about to release new version of their operating system, AOS 5.0, it is time to revisit this topic again.

Even though AOS 5.0 is yet to be released, some info is already available in blogisphere, for more information on AOS 5.0 features please visit:

Myvirtualcloud: AOS 5.0 Features, Part1

Myvirtualcloud: AOS 5.0 Features, Part2

Life after AOS 5.0

AOS / AHV isn’t offering feature parity with Vmware. Most likely it will never have all pullies and knobs that Vmware has, as one of design principles of Nutanix is to keep things simple. Or as they put it in .Next conference:

“Complex is Competent, Simple is Genius”

Here is my previously used list as a reminder:

1. Backup
2. GPU support
3. Affinity and Anti-Affinity rules
4. Metro Availability
5. Guest Customization
6. Open vSwitch Management
7. Role Based Access Control (RBAC) (future post)
8. VM Memory Utilization & Memory Sharing (future post)
9. Multi-VM Operations (future post)
10. Automated VM Migration (future post)

Let’s go trough my list once again, this time in reverse order as last time I didn’t have time to go trough my list completely.

Automated VM Migration

Previous version of AHV / AOS had limited Dynamic or Distributed Resource Scheduler (DRS) capabilities, resource usage checking was only done during initial placement of VM. No DRS load balancing while VM was running. Vmware has had capability to migrate VMs based on CPU / Memory load for a long time. At that point Vmware was more capable.

With the latest 5.0 version AHV will also have DRS. A blogger called it DRS++. Why plus plus? Like Vmware, AHV can now redistribute virtual machines based on CPU / Memory consumption, but unlike Vmware, AHV can also make decisions based on storage location / capacity / performance and use X-fit technology to make decisions not only based on single-point-of-time, but also using trends running over longer period of time .

Yes, Vmware has SIOC and SDRS, but these don’t really work with modern flash arrays or HCI environments. In fact if you are using Vmware with Nutanix or any other platform with advanced storage auto-tiering capabilities, it is advisable to turn SIOC off

Advantage point: AHV

Multi-VM Operations

With previous version of AHV virtual machine migration a was manual operation since there was no DRS.  With Prism GUI you had to click individual virtual machines and migrate them, while you could run multiple migrations in parallel and it was fairly simple one-click operation, it was still a manual operation per virtual machine. Since Vmware had DRS capability and could automate VM migration and do it for multiple virtual machines without any manual operations, Vmware was better at time.

Now both have DRS capability and can migrate multiple VMs automatically. Even though AHV can make “better” decisions, both are capable of doing multi VM operations, so let’s call it even.

Advantage point: Tie

VM Memory Utilization & Memory Sharing

This a part where I am struggling. Yes, Vmware has transparent memory page sharing and has probably more different cool memory management techniques than any other hypervisor. I could give point to Vmware, but this is a nitty-gritty detail battle, so it would be somewhat similar as declaring a winner in head-to-head comparison for two cars and deciding winner based on the fact that it was assembled by using 1200 Metric thread bolts, when the competition was assembled by using only 1000 Imperial thread bolts. For 99,99  % of car buyers this is irrelevant.

If you think that for your business case a given memory management technique gives clear advantage and has all the nuts and bolts otherwise required, by all means use Hypervisor with that feature.

Advantage point:

• if you prefer metric thread bolts, Vmware
• if you prefer imperial thread bolts, some other hypervisor

Role Based Access Control (RBAC)

While new AOS self-service portal isn’t exactly the same thing as RBAC, it can provide RBAC functionality + much more .

Advantage point: AHV

Open vSwitch Management

With AOS 5.0 Network management has taken quite big leaps. First of all much more can be done from Prism GUI, but on top of that you can actually manage VLANs for select switch vendors from Prism, no more configuring VLANs for VMs with Prism and then going to physical switch to configure those VLANs again.

Advantage point: AHV

Guest Customization

No change

Advantage point: Vmware

Metro Availability

No change

Vmware is still your choise of Hypervisor, if MetroAvailability is required.

Hyper-V is supported with synchronous replication, but with two separate Hyper-V clusters and invoking DR requires many manual operations.

No MetroAvailability support for AHV

AOS 5.0 version comes with witness or tie-breaker capability for MetroAvailability. (But only with Vmware hypervisor)

Advantage point: Vmware

Affinity and Anti-Affinity rules

Both AHV and VMware have them now, obviously with two manufacturers there are differences, but since both have them, let’s call it even.

Advantage point: Tie

GPU support

No change

No support for GPUs for AHV as of AOS 5.0, I guess that Nutanix is still waiting for GPU device drivers for KVM from Nvidia.

Now that Nutanix also supports Xen Server as a hypervisor for Citrix environments and you can use GPU cards with Xen Server, there is at least a choice of hypervisors available. But in the context of this blog:

Advantage point: Vmware

Backup

With  AOS 5.0 Nutanix will introduce hypervisor agnostic change block tracking API. Backup application vendors can hook into Nutanix snapshot information via REST API 3.0 and enable their backup software to use Nutanix native snapshots. List of currently supported backup software vendors was not available yet.

Yes, Vmware has more options for backup software and most likely will do so in near future.

If your backup software supports Nutanix snapshots, there is clear advantage in using them, even with Vmware. You can use the same software for backing up both AHV and Vmware and should you decide to run both or change your hypervisor, there is no need to change you backup application and/or backup / restore procedures.

Also Nutanix has better mechanism in making snapshots than Vmware, no penalty while removing snapshots and no orphaned delta files.

Advantage point: Too many variables to declare a clear winner, Vmware has some advantage as there are more backup software options, but Nutanix support will soon follow with some players. Nutanix has better way of doing snapshots than Vmware

Conclusion

Yes, there are still cases where Vmware hypervisor is required, like Metro Availability and GPU usage. AHV is taking quite big leaps in catching up with Vmware, in some cases even surpassing Vmware capabilities, like with new DRS or Network management capabilities. Compare features that are relevant to YOUR business case, if feature is not needed, there is not much point in making decision based on whether that feature is available or not.

Yes, having more features or option to use certain feature in the future might be a good thing. But like your daily driver is NOT a moving truck, just because you happened to need one a year go while moving, you should not choose your hypervisor based on rarely needed feature.