vSphere cluster: max 4 ESX hosts per “location” because of HA limitations?
Not a lot of info is found when you Google for manually selecting/fixing the primary HA nodes in a VMware VI or vSphere environment. Of course Duncan Epping has a couple of extremely interesting posts on Yellow-Bricks.com concerning HA even when it comes down to selecting or promoting the HA status of ESX nodes (a must read!), but I want more …
Let’s start with what I assume to know about HA:
- HA works with primary and secondary HA nodes
- The primary nodes are aware of the states and configs of all nodes in an HA cluster
- The secondary nodes depend on the primary nodes
- There is an supported limit of 5 primary HA nodes per cluster
- The first 5 ESX hosts that are added in a HA cluster are initially defined as primary HA nodes
- All the other hosts that are added to the HA cluster are configured as secondary HA nodes
- There’s a way to configure a HA node as primary or secondary, however it’s not possible to configure an ESX host as a “fixed” primary HA node:
… Continue Reading
vSphere bug can bring down entire cluster (not fixed in Update1).
Last month I was on-site at one of my customers and experienced a major problem on the vSphere environment. We suddenly experienced about 150 virtual servers running on 16 hosts in 2 clusters (on the same SAN) going in jabber-mode. They froze, which made them unavailable for pings and other traffic. The freeze moment varied from 1 to 30 seconds. After that the VM’s went back on-line again. This seemed to happen in groups of about 10 to 30 VM’s.
Pretty soon we saw in the logs that a VMFS LUN was removed by one of the SAN administrators. This LUN was still attached to all the ESX hosts in that cluster but was not “in use”, meaning, there were no VM’s running on it.
Off course the unclean removal on SAN-level of a LUN before detaching it from the ESX hosts is not the way to do this but that what I just described shouldn’t have happend!
The quick solution was … Continue Reading
Time to vote for your favorite bloggers
First of all: Happy new year and I wish you all a fantastic 2010! In this first post of the year on Virtualfuture, I want to bring the latest survey of Eric Siebert’s top 25 “VMware and virtualization bloggers” to your attention. Currently Virtualfuture.info is ranked at number 17, which I’m very proud of. I’m not saying I deserve to be in the new upcoming top 25 of Virtualization bloggers, but if you like what we’re doing, our Application virtualization comparison chart for example or our event reports (VMworld, Synergy) and our regular blogging, please give Virtualfuture.info a vote as well.
Large locally attached storage
We all know that ESX supports LUNs / Disks up to 2TB (minus a few kb) but what happens when a larger locally attached disk is connected to a host?
This is what I have noticed when I tried to create a large volume on my own ESX white box with more than 2TB locally attached storage: it only allowed me to create a volume with the space above the 2TB. In my situation I got a 48 GB volume on a 2048 GB LUN. Also, this ”2TB” volume, which I created with the vmkfstools commandline utility, was useless because I could not create a single VM on it. … Continue Reading
Citrix XenDesktop 4 released and available for download
The moment is here, XenDesktop 4 is available!
Much awaited and true to their promise Citrix has just officially made XenDesktop 4 available for download on the download page of MyCitrix.com : http://www.citrix.com/English/ss/downloads/results.asp?productID=163057 (you need to be registered and login).
