Tag Archive: vSphere

Apr 30

With vSphere 5.0 and HA can I share datastores across clusters?

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April 30, 2012

I have had this question multiple times by now so I figured I would write a short blog post about it. The question is if you can share datastores across clusters with vSphere 5.0 and HA enabled. This question comes from the fact that HA has a new feature called “datastore heartbeating” and uses the datastore as a communication mechanism.

The answer is short and sweet: Yes.

For each cluster a folder is created. The folder structure is as follows:

/<root of datastore>/.vSphere-HA/<cluster-specific-directory>/

 

The “cluster specific directory” is based on the uuid of the vCenter Server, the MoID of the cluster, a random 8 char string and the name of the host running vCenter Server. So even if you use dozens of vCenter Servers there is no need to worry.

Each folder contains the files HA needs/uses as shown in the screenshot below. So no need to worry around sharing of datastores across clusters. Frank also wrote an article about this from a Storage DRS perspective. Make sure you read it!

PS: all these details can be found in our Clustering Deepdive book… find it on Amazon.

“With vSphere 5.0 and HA can I share datastores across clusters?” originally appeared on Yellow-Bricks.com. Follow us on Twitter and Facebook.
Available now: vSphere 5 Clustering Deepdive. (paper | e-book)

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Permanent link to this article: http://www.startswithv.com/2012/04/30/with-vsphere-5-0-and-ha-can-i-share-datastores-across-clusters/

Apr 25

What is das.maskCleanShutdownEnabled about?

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April 25, 2012

I had a question today around what the vSphere HA option advanced setting das.maskCleanShutdownEnabled is about. I described why it was introduced for Stretched Clusters  but will give a short summary here:

Two advanced settings have been introduced in vSphere 5.0 Update 1 to enable HA to fail-over virtual machines which are located on datastores which are in a Permanent Device Loss state. This is very specific to stretchec cluster environments. The first setting is configured on a host level and is “disk.terminateVMOnPDLDefault”. This setting can be configured in /etc/vmware/settings and should be set to “True”. This setting ensures that a virtual machine is killed when the datastore it resides on is in a PDL state.

The second setting is a vSphere HA advanced setting called “das.maskCleanShutdownEnabled“. This setting is also not enabled by default and it will need to be set to “True”. This settings allows HA to trigger a restart response for a virtual machine which has been killed automatically due to a PDL condition. This setting allows HA to differentiate between a virtual machine which was killed due to the PDL state or a virtual machine which has been powered off by an administrator.

But why is “das.maskCleanShutdownEnabled” needed for HA? From a vSphere HA perspective there are two different types of “operations”. The first is a user initiated power-off (clean) and the other is a kill. When a virtual machine is powered off by a user part of the process is setting the property “runtime.cleanPowerOff” to true.

Remember that when “disk.terminateVMOnPDLDefault” is configured your VMs will be killed when they issue I/O. This is where the  problem arises, in a PDL scenario it is impossible to set “runtime.cleanPowerOff” as the datastore, and as such the vmx, is unreachable. As the property defaults to “true” vSphere HA will assume the VMs were cleanly powered off. This would result in vSphere HA not taking any action in a PDL scenario. By setting ”das.maskCleanShutdownEnabled” to true, a scenario where all VMs are killed but never restarted can be avoided.

If you have a stretched cluster environment, make sure to configure these settings accordingly!

“What is das.maskCleanShutdownEnabled about?” originally appeared on Yellow-Bricks.com. Follow us on Twitter and Facebook.
Available now: vSphere 5 Clustering Deepdive. (paper | e-book)

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Permanent link to this article: http://www.startswithv.com/2012/04/25/what-is-das-maskcleanshutdownenabled-about/

Oct 11

DynamicOps is First with Full-Featured, Flexible Platform for On-Demand IT

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October 11, 2010

DynamicOps steps up its game with DynamicOps Cloud Automation Center (DCAC)

DynamicOps is extending its expertise in virtualization and private cloud management by introducing the DynamicOps Cloud Automation Center (DCAC). It is the industry’s first full-featured, flexible platform for defining and rapidly automating the delivery and management of on-demand IT services on a shared multi-tenant private or public cloud infrastructure.

Read more in the DynamicOps DCAC Press Release

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Permanent link to this article: http://www.startswithv.com/2010/10/11/dynamicops-is-first-with-full-featured-flexible-platform-for-on-demand-it/

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