Tag Archives: Virtualization - Page 2

Fix a CloudStack instance stuck in an incorrect state

In Apache CloudStack it is possible for the database to become out of sync with what is actually happening. For instance if there is a network issue preventing CloudStack from correctly connecting to the hypervisor or virtual machine and you try to shutdown or reboot a server, the action may not actually take place despite the state in the CloudStack database being modified.

This can cause the instance to show as being in the ‘starting’ or ‘stopping’ states for instance, however the virtual machine may already be fully booted or completely powered off. To fix this we can manually update the management database to the correct state.

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Free Virtualization Software for Windows

There is a lot of free virtualization software available for your to download and install, here we cover some of the best free options available for you to use in Windows.

These options can be installed within your existing Windows operating system installation, allowing you to run a virtual machine (VM) running an entirely separate operating system within. For example this will allow you to run multiple instances of Linux and Windows desktop clients or servers.

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How to convert an OVA virtual machine to VHD

Today I received a virtual machine OVA file exported from VMware, I needed to import this into Apache CloudStack where XenServer was the hypervisor.

To do this I first needed to convert the OVA/OVF to VHD, this post covers how it’s done.

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Virtual machine not powering on in Citrix XenServer 6.2

Today I connected to a CentOS 6 server via SSH and quickly noticed that the file system was in read only mode, after checking a few other Linux servers on the same XenServer host it quickly became apparent that there had been a network issue between the storage and compute layers which caused the Linux file systems to go read only in order to protect themselves.

After not being able to do anything useful within the operating system such as remounting the file system as read/write, I decided that it was time to reboot and force a file system check to pick up and fix any problems, however once the server had shut down it did not power back on as part of the restart task, it also did not power back on when attempting to start it up. This only happened to one VM, all of the others powered back on fine and worked as expected.

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