Wednesday, October 26, 2016

VMware ESXi - vmkvsitools

This blog article is about a very useful command master command with the name vmkvsitools which can retrieve specific information about the host and ESXi processes. The name is a short name for “VMkernel Sys Info Tools”. Sounds interesting? Let’s dig into it.

You find vmkvsitools under /usr/sbin/vmkvsitools. Vmkvsitools includes the below shown 16 subcommands which are a link to /bin/vmkvsitools (/bin is a link to /usr/sbin). That means you don’t have to put vmkvsitools in front of these commands. I am sure certain ones you have seen before like ps, vdf, update etc. but you eventually never knew that they were part of vmkvsitools. First let’s see what the command has when using help.

VMware ESXi - vmkvsitools lspci

Lspci is a short name for list PCI (Peripheral Component Interconnect) devices. PCI is a standardised bus to attach different kinds of hardware on the motherboard of a x86 system. Many devices such as I/O cards (e.g. HBA, CNA, network cards) are PCI cards. In current hardware these PCI is replaced by the next generation standard PCIe (Peripheral Component Interconnect Express). PCIe delivers a high-speed serial computer expansion bus standard to replace PCI, PCI-X (Peripheral Component Interconnect eXtended) and AGB (Accelerated Graphics Port) bus standards. It is also expected that SATA will get replaced by PCIe which happens today already as Flash gets faster and there is a need for high demanding performance. With -h you see below that there are a few options to get info from detailed, over hex dump to verbose output.

Tuesday, October 25, 2016

Understanding I/O - What about IOPS, Throughput, Latency and I/O Size

This blog article is about one of my most favourite topics with just two letters: I/O. Why? Because really everything around virtualization and storage is about how I/O works and there is not much fun in life without Input/Output. And yes there are many blog articles about I/O but not so much from the I/O size perspective. So hopefully this will help you with some confusion. Let’s start very simple and define this four keywords:

Thursday, October 20, 2016

VMware ESXi How to find Firmware and Driver version

This blog article is about how to find a particular driver and firmware of an I/O device like a HBA, Network card etc.! For VMware VSAN there is a nice health checker now but not everyone is using VSAN and not everything in a ESXi system involved in VSAN like Network Cards and local devices.

VMware ESXi locking and how to kill a frozen VM

This blog article is about how to kill a frozen VM. Working in technical support you often get cases where let’s name it: “something went wrong”. This could be a great variety from storage issues or other process running on the particular ESXi which still hold on a lock file as well as many other reasons. This blog article is structured in the way that I start with the different ways how to kill a VM followed by several troubleshooting techniques like: which host has the lock, is there eventually an APD (All Path Down) or even PDL (Permanent Device Loss) happening.