Low Power VM Lab Pt II

By | May 30, 2014

This has been a while coming but anyways better late then ever. Since I wrote the original article I have been using a number of different hyper-visors, also the hosts number has grown to three. Here’s how it went.

To start with I had everything running with VMWare which I had some interest in as it was what we mostly use at work (we have Hyper-V hosts also). However once I got the second Intel NUC I started trying some other hyper-visors. As stated in the first article this went something like this:

ESXi (free version) to Hyper-V (free version) to XenServer (free version) to XCP (Open Source) then after some time back to Hyper-V as we were starting to use this more at work. However once I felt comfortable with Hyper-V and most of it’s features I started a couple of weeks back to look at putting everything back to XCP.

There were a number of reasons for this but I really like Hyper-V a lot and it will have real potential at work to save us a lot of money on VMWare licences but once you have more than a couple of hosts unless you are running AD at home it gets a bit messy. Of course we will not have these issues at work but at home I just liked the simplicity of XCP for what I was trying to do.

There was also another reason I moved off VMware and Hyper-V at home and that was just from the point of view that I didn’t want to use iSCSI here at home. I am using a Synology as per first article http://www.hardstaff.com/techo/63-lower-power-vm-lab?showall=&start=1 and using it like this the backup process for iSCSI LUNS adds an extra level of complication I could live without. Those LUNS are also actually just a big file that lives on the Syno. I didn’t feel too comfortable with that. Don’t get me wrong it works fine but it’s fiddly to setup, mount all the LUNS as drives, format etc etc

Adding an NFS SR in XenCenter

This is where XCP was (in my situation) just so much easier. XCP allows you to simply use NFS not only as a an ISO repository but also as a SR as they call it, ie Storage Repository. This works extremely well with the Syno NFS and is very quick to set up and I don’t have to make guesses about LUN size. Each SR see the size of the volume it is on. Whats more, you can actually browse it and see the actual VHD files. My next step is to run a Syno to Syno backup while the VM’s are running and see what I get on the backup box and see if that VM can be started elsewhere, this would just be for DR. Hyper-V replication is a much nicer way to do this of course but I could (and should) write another article about that.

NFS SR in XenCenter

Here you can see the NFS share called nfs2 that is connected to the host xen2, all the VHD files are visible on the Synology file system.

There was also one other point in favor of XCP for me. With both Windows Server 2012 and VMWare I had to do hacks to get the NIC in the NUC to work. With XCP it’s just works. I don’t like hacked systems and using unsupported configurations much so after about 8 months of using Hyper-V and feeling very comfortable with it I decided to put all the hosts back to XCP only to discover XCP was no more. Well it was no more because Citrix fully open sourced XenServer making XCP more or less redundant as it was basically an open source XenServer. Thats simplifying things somewhat but more here http://www.xenproject.org/component/content/article/100-misc/148-xcp-and-xenserver-faq.html (Nice to see xenproject.org using Joomla). The only downside of this is you have to install updates form the command line as you can’t use XenCenter to do that unless you have a licence, but apart form that it seems most everything else works.

Most of my VM running on XenServer including this web server, all using Debian 7

So, moving from Hyper-V to XenServer was relatively painless. Shut down VM, convert any VHDX to VHD, import into XenServer through XenCenter and that was pretty much it, after first boot install tools and away you go. I did a number of Windows 2012 / 8 and Debeian boxes and they all booted first time. I had experimented with local storage but with a single spindle it can get a bit slow, depends on what you are doing. I don’t have local RAID which would be fine. Having all the VM storage on the Synology with 3 spindles really makes a difference.

Thats about it for this update.


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