vSphere 6.5 Update 1 Released

VMware have recently announced the general availability of vSphere 6.5 update 1. Full details around this release can be found in the reference links at the bottom of this post so I’ll just call out a few key points from these sources.

Over the last 8 months there have been several patches and fixes released to address bugs and issues in the GA release of 6.5, all of which are included in update 1.

This release also addresses a previous limitation in the upgrade path. For those of you running 6.0 U3 there was previously no supported upgrade path to 6.5. Thankfully this has been resolved.

vSphere Client Improvements

New functionality has been added to the HTML 5 client around host-centric operations. Areas such as VDS management, datastore management and host configuration have seen a big improvement in functionality. VMware are saying the vSphere Client has about 90% general workflows completed with more to come in future releases. With Adobe announcing the end support of its flash plugin by 2020 I would hope to see feature parity long before then as well as full 3rd party vendor plugin support.

vCenter Foundation

VMware say they have had feedback from smaller customers saying the three host limitation was too small. With 6.5 update 1 vCenter Foundation will now support a maximum of four hosts. This is great news and I wonder if this has anything to do with making vSAN a more attractive option to those smaller environments. Whilst vSAN requires a minimum of three hosts (or two plus witness with ROBO) there has always been questions raised around data availability during host maintenance and the risks involved. Please note this is specifically for vCenter Foundation only and not vCenter Essentials or Essentials Plus.

vCenter Server Scalability

With this release VMware have increased some of the maximums related to SSO domains. Some of these include

  • Maximum vCenter Servers per vSphere Domain: 15 (increased from 10)
  • Maximum ESXi Hosts per vSphere Domain: 5000 (increased from 4000)
  • Maximum Powered On VMs per vSphere Domain: 50,000 (increased from 30,000)
  • Maximum Registered VMs per vSphere Domain: 70,000 (increased from 50,000)


There is an incremental release to vSAN which is now 6.6.1 and includes some new capabilities with using vSAN with vSphere Update Manager (VUM). This version of vSAN works alongside VUM to ensure that when you update your cluster the hardware is kept in a supported state. During the update process recommendations are automatically generated using information from the VMware Compatibility Guide (VCG). This helps both simplify the upgrade process and give a more predictable experience.

Many customers typically delay upgrading their systems on a major software release until the first update or patch for stability reasons. Now 6.5 update 1 is here now is the perfect time to start planning that upgrade.

A quick side note - on checking the VCG ESXi 6.5 update 1 is supported on some of the popular Dell EMC servers. This isn’t an exhaustive list so I’d encourage you to check the VCG if your server isn’t listed.



R720/720xd, R730/xd, R740/xd



Reference links and further reading.