I run a Supermicro Xeon-D based for home lab purposes. One of the VMs on the Lab is my fileserver, which has four physical 3TB disks passed through as RDMs. You can read more on my (pretty awesome) home lab, since it’s physically small, but very powerful and incredibly versatile:

  1. Running a virtual gaming rig using a Xeon D server, a GFX 750Ti, PCI passthrough and a Windows 10 VM
  2. Build a Xeon D-1500 (Open) Home Lab with me?

The issue

In the last couple of months, I’ve tried upgrading to ESXi 6.5.0d twice. Both times, my fileserver would not play nice after the upgrade, showing 750GB disks instead of the regular ~2,7TB. Also, when accessing files, the disks would go offline and not come back.

This had me scratching my back, but I never took the time to investigate and instead reverted to good ol’ ESXi 6.0.

The solution

Recently, I came across this tweet by Anthony which links to a very elaborate comment on his blog. In a nutshell, ‘APR911‘ found a solution to the RDM issue I experienced earlier.

So, the solution is incredibly simple, just disable the native VMware driver for AHCI and reboot the host.

esxcli system module set --enabled=false --module="vmw_ahci"

I’ll leave the rest of the context and explanation to Anthony, so make sure to read his blog post ‘HOMELAB – SUPERMICRO 5028D-TNT4 STORAGE DRIVER PERFORMANCE ISSUES AND FIX‘.