For those who have plans upgrading their environment from vSphere 6.0 to 6.5 Update 1, I would suggest postponing this until VMware resolves issue documented in KB 2151749.
Hosts will be affected if they equipped with 10 Gbps NICs.
The only workaround that the vendor has at the moment is to downgrade ESXi to 6.0 Update 2.
17/10/2017 – Update 1: According to VMware GSS, this issue is going to be “resolved in ESXi 6.5 Patch 02, which is schedule to release this month (The release date may change without notice).” Please refer to the SR #17599111410 when contacting GSS for more information.
VMware has just released a new hotfix for ESXi and vSAN (KB 2151081) urging customers with all-flash configuration with deduplication enabled to upgrade their environment as soon as possible. This patch resolves data corruption issue which might appear in rare circumstances.
The affected versions of vSAN include 6.5, 6.6, and 6.6.1.
06-10-2017 – Update 1: As listed in KB 2151042, similar issue has been fixed for ESXi 6.0.
I have a habit of reading all new KB articles published by VMware every week. Not only is it give a visibility of the current issues that VMware products have, but it helps to be proactive with learning some behaviour and workarounds and prepared to remediate them if required.
Therefore, after writing a few blog posts about vCenter 6.5 and IPv6 here and here, it caught my eye that ESXi 6.5 Hosts could also fail with a Purple Screen of Death when IPV6 is disabled.
VMware has published a KB 2150794 that explained this behaviour.
The only workaround at this moment is to re-enable IPv6 on all hosts in your environment.