Update (01.08.2017) - the latest ESXi 6.5 update 1 (build 5969303) seems to fix the performance problems. Read below on how to upgrade your hosts...
VMWare recently released it's VSphere line versioned as 6.5. I do not recommend to install it yet in a production environment - but it should be fine for your homelab.
Im reading several blog posts about disk performance problems with the new standard AHCI-driver (native vmw_ahci driver).
I noticed the problems when I started to deploy a new VM from an existing OVA and also when I moved a VM from one datastore to another (Max. Disk-read/write performance 10 MB/s). Also chrome uploaded the OVA with a max. speed of 16 MBit/s.
Older ESXi hosts were using the legacy vmklinux drivers and in general the new native drivers should offer a better performance and lower overhead as those are build directly for ESXi.
You can check if your adapters are using the native VMWare driver in the GUI by going to STORAGE -> ADAPTERS:
If you are experiencing slow disk performance you can disable the new native driver module and reboot your hosts (enable SSH and log in):
>> esxcli system module
ESXi should fall back to the legacy ahci drivers and disk performance should be a lot better again.
On my hosts the OVA now uploaded at 300 MBit/s and Disk-read/write performance is back to the usual values.
You can also check if the module is enabled or disabled by running the following cli-command:
>> esxcli system module list
The affected module version for the native AHCI driver reports as:
vmw-ahci 1.0.0-32vmw.618.104.22.16864106 VMW VMwareCertified 2016-11-20
Update (27.03.2017) - the problem still exists for vmw-ahci version:
Update (01.08.2017) - the latest ESXi 6.5 update 1 (build 5969303) seems to fix the performance problems.
It includes vmw-ahci 1.0.0-39vmw.622.214.171.12469303
You can upgrade your ESXi 6.5 host by cli using the following commands:
esxcli network firewall ruleset set -e true -r httpClient esxcli software profile update -p ESXi-6.5.0-20170702001-standard \ -d https://hostupdate.vmware.com/software/VUM/PRODUCTION/main/vmw-depot-index.xml esxcli network firewall ruleset set -e false -r httpClient
Or download and boot the ESXi 6.5 Update 1 ISO to upgrade your host.
I hope this guide will help you until VMWare fixed the AHCI drivers for ESXI 6.5.