XenServer / VMWare question

Guest2 · 7 Apr 2010 at 17:03

A couple of week ago I was testing VMWare and all was starting to go well.

My boss spoke with our Citrix supplier about us maybe moving to VMWare. They quickly came in for a meeting with him and organised a XenServer presentation.

We both went to this and all went well. I tested and then setup Xen Server which now runs our live SQL database and secondary DC.

We have 2 servers, one live and one for testing. The live server is an HP Proliant DL360 G5, the test server is a HP Proliant DL120 G5.

I exported the DC Virtual machine from the DL360 as a backup to our file server which took about 4 minutes. Excellent, then imported it to the DL120. It imported in 4 minutes.

I then turned on the new DC on the test server and it fired up fine.

What I dont understand is how the drivers are working perfectly with the DC on the test server. I know some of the drivers will be similar because they are both HP but how it possible that its working perfectly?

In the presentation from our Citrix suppliers the guy was explaining about having to use Acronis software to clone virtual machines and it would sort out the different drivers when moving VMs. However it appears to have imported perfectly

Guest2 · 8 Apr 2010 at 10:26

Yeh thats what I thought too. In the Xen presentation they had 2 identical servers. He was explaining about high availability and how it works and the different levels of protection available nad that it must require identical servers to work

The person giving the presentation with many years of Citrix knowledge said two servers arrived and was supposed to be identical, however the processors were a different revision in one of the boxes. He swapped 2 of the processors over to the other box so they were both running 2 revision 1 and 2 revision 2. This then worked properly.

Surely there isnt much point buying different servers if one of the main features does not work correctly?

Why did he explain about Acronis being able to clone VMs and sort out the different drivers?

Thanks

Edit - sorry unp|dissy, if you use Xen a lot could I ask a couple more questions please...

When I close Xen Center I need to log back in to the servers. Can this be turned off or an option be enabled to save password and automatically connect to all servers on open?

I have created a template of Server 2003 standard. I then created a VM from this templete. It obviously has the same computer name as the templete. I though the idea of a template was that you have the VM as before but it has a blank slate in regards to things like IP address and computer name so there are no conflicts. Is there a way of setting the computer name to blank in a template?

On one of my servers I am trying to create a local storage for Windows ISO files. I go to local storage > storage > add disk > 80GB, called ISOs. How do I now copy ISOs to this 80gb virtual drive? I have tried going to the menu bar and selecting Storage > New storage repository > ISO library > windows CIFS. In share name i then put \\xenserver\ISOs (my test server is just called xenserver) I press finish and it says "Creating SR, DNS lookup failed, the hostname could not be resolved. check your settings and try again" I have also tried the IP address insstead of the server name and it does the same thing

Cheers

Guest2 · 8 Apr 2010 at 13:48

What is a guest OS customisation, how do i do one in Xen?

Thanks guys

Guest2 · 9 Apr 2010 at 10:38

Trojan said:
Sorry, as said, I've not used XenServer before, but there must be a way when deploying a VM to customise the host name, NIC settings etc. Try having a play around with the deployment menu and see if there's an advanced, or something you've missed.

In vSphere it's a simple case of selecting customise Guest OS.

Thanks. Reading this is sounds like you run sysprep after the VM is created

http://docs.vmd.citrix.com/XenServer/4.0.1/guest/guest.html

3.4. Preparing to clone a Windows VM

In Xen you can change a VMs network settings, RAM, CPUs and disks. These are the new VM wizard options (there is no advanced)...

Template - the os template
Name - just the name for Xencenter
Location - location of install (dvd or iso store)
Home Server - which server to put it on
CPU & Memory - No. of cpus and ram allocation
Virtual disks - size of the virtual HD
Virtual interfaces - netowork interfaces, can add more or delete
Finish - start vm automatically

I created a new VM, ran updates etc then ran sys prep. After sys prep I converted this to a template. I take it that when its re-used I just need to change the IP and name of computer on the netowrk.

Does Sysprep only take care of SIDs? "Computers running Windows operating systems use a Security ID (SID) to uniquely identify themselves. When cloning a Windows VM, it is important to take steps to ensure the uniqueness of these Security IDs. Cloning an installation without taking the recommended system preparation steps can lead to duplicate SIDs and other problems. Because the SID identifies the computer or domain as well as the user, it is critical that it is unique"

If I didnt run sys prep and I ran 2 machines on a netowork, but just renamed the computer name and IP addresses. What problems would arise from having 2 similar SIDs?

I dont understadn how sys prep works because even after i ran it i made it a template so surely the template will have its own SID that will be used for all VMs created from the template. ( unless sys prep gives it a blank SID that automatically created further down the line when the new VM is used)

As you can tell all this type of stuff is new to me!

Thanks for the help