ESX Vs XenServer - Technical Comparison

In the last post, had written about the free version of XenServer and the impacts in the market.

Now to the real technical differences between ESX and XenServer. The areas where XenServer is lagging behind ESX are:

1. Memory Overcommit - Though MS and Citrix have been trying to push this as just a nice to have feature, overcommit really makes a big difference in the TCO of the solution and VMWare has never missed an opportunity to point this out. Believe XenServer should be getting this in its next release.

2. Resource Pools - VMWare has got its foundations really strong by defining Clusters and Resource Pools. Resource Pools provides the IT admins to allocate resources to a group of VMs (belonging to a specific department). VMWare has cleverly leveraged this in its management products including LabManager and StageManager.

3. Distributed Resource Scheduler (DRS) - Another reason why ESX is the darling of IT admins. DRS clubbed with HA has made life very peaceful for IT admins around the globe. Though XenServer already has HA (infact claims to have Fault Tolerance), hoping to see DRS also get into the solution soon.

4. Strong Community Participation - This is something that VMWare has built over the years. VMWare communities and forums are a wealth of ESX tips and tricks and it is going to take Citrix years to catch up on that. Hope Citrix focuses on this as it gets more traction in the enterprises.

Areas where Citrix has an edge over VMWare include Storage Integrations (will put up a separate post on that) and XenServer HA (Zero downtime) technology OEMd from Marathon. Have not really heard much about the technology from Marathon so will not comment on that.

Have focused only on the difference between VC+ESX and XenCenter+XenServer. Will probably put up a different post highlighting the differences in the management stack.

Feel free to comment on any areas that I have missed out.

Update: Had missed out on a minor but useful feature that XenCenter provides. The ability to search for VMs based on different criteria. Believe this should be a useful feature as the virtualization deployments grow in size. Had noted VMWare was getting this into the next version of vCenter!!!