Vsphere 6.5 Slot Size
You can also have option to choose “Slot Policy”. This is the default option prior to vSphere 6.5. Slot Size is defined as the memory and CPU resources that satisfy the reservation requirements for any powered-on virtual machines in the HA cluster. In ESXi 6.5 the size of the VPD is dependent on the number of cores in the CPU package. This results in a virtual NUMA topology of VPDs and PPDs that attempt to resemble the physical NUMA topology as much as possible.
[NOTE] : I decided to republish this post with a new heading and skip right to the meat of the issue as I’ve had a lot of people reach out saying that the post helped them with their performance issues on ESXi 6.5. Hopefully people can find the content easier and have a fix in place sooner.
The issue that I came across was to do with storage performance and the native driver that comes bundled with ESXi 6.5. With the release of vSphere 6.5 yesterday, the timing was perfect to install ESXI 6.5 and start to build my management VMs. I first noticed some issues when uploading the Windows 2016 ISO to the datastore with the ISO taking about 30 minutes to upload. From there I created a new VM and installed Windows…this took about two hours to complete which I knew was not as I had expected…especially with the datastore being a decent class SSD.
- Target audience: IT Administrators and Solution Architects planning to leverage HPE 3PAR StoreServ Storage within a VMware vSphere 6.5 environment. This white paper is based on testing performed in March 2017 with HPE 3PAR OS 3.3.1 and VMware vSphere 6.5.
- VSphere 6.5 is now available and with every release VMware makes changes to the configuration maximums for vSphere. Since VMware never highlights what has changed between releases in their official Configuration Maximum 6.5 documentation, I thought I would compare the document with the 6.0 version and list the changes between the versions here.
I created a new VM and kicked off a new install, but this time I opened ESXTOP to see what was going on, and as you can see from the screen shots below, the Kernel and disk write latencies where off the charts topping 2000ms and 700-1000ms respectively…In throuput terms I was getting about 10-20MB/s when I should have been getting 400-500MB/s.
ESXTOP was showing the VM with even worse write latency.
I thought to myself if I had bought a lemon of a storage controller and checked the Queue Depth of the card. It’s listed with a QD of 31 which isn’t horrible for a homelab so my attention turned to the driver. Again referencing the VMware Compatibility Guide the listed driver for the controller the device driver is listed as ahci version 3.0.22vmw.
I searched for the installed device driver modules and found that the one listed above was present, however there was also a native VMware device drive as well.