Planet vSphere-land

Replaced certificates and get vSphere HA Agent unreachable? I have heard this multiple times in the last couple of weeks. I started looking in to it and it seems that in many of these scenarios the common issue was the thumbprints. The log files typically give a lot of hints that look like this: [29904B90 verbose 'Cluster' opID=SWI-d0de06e1] [ClusterManagerImpl::IsBadIP] <ip of the ha ma...

Last week on twitter someone mentioned he received the error that he had less than two vSphere HA heartbeat datastores configured. I wrote an article about this error a while back so I asked him if he had two or more. This was the case, so next thing to do was to “reconfigure for HA” to clear the message hopefully. The number of vSphere HA heartbeat datastores for this host is 1...

Last week there was a question on VMTN about VM Monitoring sensitivity. I could have sworn I did an article on that exact topic, but I couldn’t find it. I figured I would do a new one with a table explaining the levels of sensitivity that you can configure VM Monitoring to. The question that was asked was based on a false positive response of VM Monitoring, in this case the virtual ma...

The following content is in Spanish, the language in which the webinar is presented.El 25 de abril en ProfessionalVMware #vBrownBag LATAM @aantigua presentó el tema @cloudphysics

I have been having these discussions with our engineering teams for the last year around guaranteed restarts of virtual machines in a cluster. In the current shape / form we use Admission Control to guarantee virtual machines are restarted. Today Admission Control is all about guaranteeing virtual machine restarts by keeping track of Memory and CPU resource reservations, but you can imagine...

Another interesting question in the PowerCLI Community today. David wanted to know if it was possible to track which VMs had been failed over to another ESXi host by HA. With the Get-VIEventPlus function from my Get the vMotion/svMotion history post it is easy to get that informatiom from the Tasks and Events that are kept in the vCenter database. But which event to look for ? The Making Of In...

The following content is in Spanish, the language in which the webinar is presented.El 28 de marzo 2013 en ProfessionalVMware #vBrownBag LATAM se presentó el tema “HA alta disponibilidad”  por Raymundo Escobar Castañeda  @elnemesisdivina(tip: se puede ampliar a pantalla completa y cambiar la calidad de reprodución a HD 720p).vBrownBag en castellano es una expansión de la plat...

I have had this question many times by now, what is “Current Memory Failover Capacity” that is shown in the cluster summary when you have selected the “Percentage Based Admission Control Policy”? What is that percentage? 99% of what? And will it go down to 0%? Or will it go down to the percentage that you reserved? Well I figured it was time to put things to the test...

I had question today about using the advanced settings to set a minimal amount of resources that HA would use to do the admission control math with. Many of us have used these advanced settings das.vmMemoryMinMB and das.vmCpuMinMHz to dictate the slot size when no reservations were set in an environment where the “host failures” admission control policy was used. However what m...

I have had this question multiple times now, how do I disable datastore heartbeating? Personally, I don’t know why you would ever want to do this… but as multiple people have asked I figured I would write it down. There is no “disable” button unfortunately, but there is a work-around. Below are the steps you need to take to disable datastore heartbeating. vSphere Cli...

I wrote about how vSphere HA 5.x restart attempt timing works a long time ago but there appears still to be some confusion about this. I figured I would clarify this a bit more, I don’t think I can make it more simple than this: Initial restart attempt If the initial attempt failed, a restart will be retried after 2 minutes of the previous attempt If the previous attempt failed, a ...

HA admission control is quite challenging to understand as it interacts with multiple layers of resource management. In the upcoming series of articles I want to focus on the HA Percentage based admission control and how it interacts with vCenter and Host management. Let’s cover the basis first before diving into percentage based admission control. Virtual machine service level agreements HA p...

I was reading this article by Chad Sakac on vSphere DR / HA, or in other words SRM versus Stretched (vMSC) solutions. I have presented on vSphere Metro Storage Cluster solutions at VMworld together with Lee Dilworth and also wrote a white paper on this topic a while back and various blog posts since. I agree with Chad that there are too many people misinformed about the benefits of both sol...

Depending on whom you talk to or ask, you will get different views and opinions, some of them stronger than others on if magnetic tape is dead or alive as a data storage medium. However an aspect of tape that is alive are the discussions by those for, against or that simply see it as one of many data storage mediums and technologies whose role is changing. Here is a link to an a ongoing di...

Those who have configured vSphere HA have all seen that section where it asks if you want to use admission control or not. Of course if you decide you want to use it, and you should want this, then the next question that comes is which one do you want to use? I have always preferred the “Percentage Based Admission Control” policy. For some reason though there are people who thin...

This is the second in a two-part industry trends and perspective looking at learning from cloud incidents, view part I here. There is good information, insight and lessons to be learned from cloud outages and other incidents. Sorry cynics no that does not mean an end to clouds, as they are here to stay. However when and where to use them, along with what best practices, how to be ready...

This is the first of a two-part industry trends and perspectives series looking at how to learn from cloud outages (read part II here). In case you missed it, there were some public cloud outages during the recent Christmas 2012-holiday season. One incident involved Microsoft Xbox (view the Microsoft Azure status dashboard here) users were impacted, and the other was another Amazon Web Ser...

I received a question today from someone who wanted to know the difference for isolation detection between vSphere 5.0 and 5.1. I described this in our book, but I figured I would share it here as well. Note that this is an outtake from the book. The isolation detection mechanism has changed substantially since previous versions of vSphere. The main difference is the fact that HA triggers a...

I just noticed these 3 cool TechPubs youtube videos, the techpubs channel has been around for a while and I have been enjoying their videos a lot. Recently a couple of new videos were released and I hadn’t gotten around to watching them yet, but these are definitely part of my favorites. One is on vSphere HA by the lead engineer: Keith Farkas (also a reviewer on our book), and two oth...

Death to false myths probably sounds a bit euuhm well Dutch probably, or “direct” as others would label it. Lately I have seen some statements floating around which are either false or misused. One of them is around Admission Control and how it impacts consolidation ratio even if you are not using reservations. I have had multiple questions around this in the last couple of weeks and...

I had this question yesterday where the error “Insufficient resources to satisfy HA failover level on cluster” comes from. And although it is hopefully clear to all of my regular readers this is caused by something that is called vSphere HA Admission Control, I figured I would reemphasize it and make sure people can easily find it when they do a search on my website. When vSphere HA ...

When answering some questions in the vSphere HA section of the VMTN forum the “poweron” file was mentioned. I have gotten some other questions as well about this file so a public blog post makes most sense. Each hosts in a vSphere HA cluster keeps track of the power state of the virtual machines it is hosting. This set of powered on virtual machines is stored the “poweron” file. ...

Frank and I decided to put the vSphere 5.1 Clustering Deepdive (paper copy) up for sale for only $ 17.95. This is a limited time offer (21st of December), so if you want to get yourself, your friend-husband-father-kids or even grandmother a nice present be quick. How’s that for a black-friday, cyber-monday, christmas / sinterklaas special? Yes indeed, the paper copy is cheaper than all e-b...

Someone reported issues that in their environment VMs could not be restarted as there were no compatible hosts available. The relevant part of the error message was: N3Vim5Fault16NoCompatibleHostE I don’t know why in this case it happened as the log files unfortunately don’t provide these details. This person had manually restarted all of his VMs and that actually worked okay. This c...

On the community forums someone asked a question around how to set “config.vpxd.das.electionWaitTimeSec”. I was looking at the documentation and it is indeed not really clear on what / where / how to set an HA vpxd.das advanced setting. This KB article kind explains it, but let me summarize it and simplify it. There are various sorts of advanced settings, but for HA three in particul...