This is a situation that never should happen, and I had to deal with it only a couple of times in more than 10y working with VMware vSphere/ ESXi. In most cases, the reason for this was the usage of thin-provisioned disks together with small datastores. Yes, that’s a bad design. Yes, this should never happen. There is a nearly 100% chance that this setup will fail one day. Either because someone dumps much data into the VMs, or because of VM snapshots.

TL;DR Jump to Windows Client Windows Server VMware vSphere/ ESXi HPE ProLiant I will try to update this blog post regularly! Change History 01-13-2018: Added information regarding VMSA-2018-0004 01-13-2018: HPE has pulled Gen8 and Gen9 system ROMs 01-13-2018: VMware has updated KB52345 due to issues with Intel microcode updates 01-18-2018: Updated VMware section 01-24-2018: Updated HPE section 01-28-2018: Updated Windows Client and Server section 02-08-2018: Updated VMware and HPE section 02-20-2018: Updated HPE section 04-17-2018: Updated HPE section