ESXi - when to pull the plug from the physical server?

[Ignatius]

A colleague and I have been looking into virtualisation recently and we seem to have settled on free ESXi (vSphere 5.1). The host server is up and running and I copied a physical server yesterday onto the ESXi host using the standalone converter installed on the physical server. The server that I copied wasn't a vital server (it has some printers but isn't a DC, file server etc.) just in case something went wrong! The process went smoothly - I assigned a static IP address and set the server name as quite distinct from the physical server. Both the physical and virtual server have been running overnight.

 

This morning, users who use the printers associated with the physical server couldn't do so, so the physical server has been unplugged from the network and the virtual server name changed to that of the physical server and everything's working fine again. Obviously, this is what we planned to do eventually, but we wanted to go at our pace with this new experience, rather than be forced do do so in an emergency by the situation that we faced.

 

Eventually, we'll need to migrate more critical physical servers, such as Exchange, Web, DC and File Server so we need to get everything completely clear. I realise that there will be an automatic entry in DNS for the newly created virtual servers but, as the names will be quite distinct (initially) from the physical servers, will it be possible to have the physical and virtual servers all up and running simultaneously? We'd like to implement the physical to virtual in stages, rather than have to pull the plug on everything and then (potentially) have to run around like headless chickens sorting out any mess that might ensue.

 

Finally, I posted here because I know there are several who use ESXi or other virtualisation platforms and this is the most active IT-related forum that I visit.

 

Thanks for your time and patience!

Edited November 20, 2012 by Ignatius

[Duke]

Others may have different opinions, but generally what I've done and seen done is to P2V (physical to virtual) a server using the VMware converter (either standalone or in vCenter - vCenter is nice as everything takes place server-side so you can keep an eye on it but don't need to leave your own PC [for example] running if it's going to take a long time) but set the converter up not to power the new virtual server up when it finishes.

 

Once it's converted, you'd normally edit the settings to turn off networking, then power the server up and make sure it runs properly. Some services that require a network connection will obviously fail, but check everything else looks okay. Don't forget to install VMware Tools. Next, clean up your hardware. You can do quite a bit of this using Device Manager (i.e. delete a Dell RAID card now that you're using VMware's SCSI 'card'), but it will probably not show you everything you need (e.g. an old NIC, which will stop you assigning the IP address you want to the new VMware NIC). To fix this open a command prompt run set devmgr_show_nonpresent_devices=1 followed by start devmgmt.msc then in the Device Manager window that pops up, do View > Show Hidden Devices. This will allow you to see all the hidden or ghosted hardware and clear it out.

 

Give the new virtual server a few reboots and make sure it's happy, and check the hostname and IP address are correct (still with VM networking not connected). You generally should not need to assign a new hostname and IP address to the virtual server. Remember that you're replacing the old physical server, not trying to run them side by side.

 

Once you're sure the virtual machine looks okay, shut down the old physical server, then shut down the virtual server, connect the VM network and power it back up. Hopefully, everything will run fine and your users will notice no difference between the old server and the new one! If you do run into issues, power down the virtual machine and turn the physical server back on, then disconnect networking on the virtual machine while you power it back up to troubleshoot it.

 

There's nothing stopping you doing one server at a time (I'd recommend it in fact), but I wouldn't P2V your DCs. Make new virtual servers and DC Promo them, let them sync up, then demote your old physical DCs.

 

Hope this helps,

Chris

Edited November 22, 2012 by Duke

[3s-gtech]

I've P2Vd a few machines now with Converter Standalone. As above, the advice is not to do DCs this way - build them fresh. Otherwise though, I've done them as straight swaps - made sure not to power up the converted VM on completion, then run the converter. When it's finished, shut down the physical machine, then fired up the VM and fixed the IP address settings. Total downtime is usually just a few minutes, but obviously some servers will have to wait until a quiet or holiday period!

[glennda]

What I would recommend doing is setting up a Network switch within ESXI with no physical network cards assigned. You can then run the VM's completely isolated from your Physical network.

 

You can convert everything and run it seperately (obivously when you do a final change I would reimport the physical machines).

[Cache]

I've P2Vd a few machines now with Converter Standalone. As above, the advice is not to do DCs this way - build them fresh. Otherwise though, I've done them as straight swaps - made sure not to power up the converted VM on completion, then run the converter. When it's finished, shut down the physical machine, then fired up the VM and fixed the IP address settings. Total downtime is usually just a few minutes, but obviously some servers will have to wait until a quiet or holiday period!

 

It's funny, I read all the details of not doing DC's and had a company come in and do the migration and setup of our VM environment. They happily P2V'd the DC which was also the main file server, antivirus server and other bits and pieces (legacy so is gradually being reduced) and just did it even with me offering to demote it and it worked fine, so I guess YMMV but with things like that I left it in their hands knowing I had a backup but if something went wrong, it wouldn't be me spending time resolving it. (I wouldn't have risked it myself)

Edited November 22, 2012 by Cache

[gshaw]

Depending on what OS is installed on the old physical servers the virtualization could be a good time to start with a clean slate and new OS.

 

We did P2V on some of the more awkward servers but migrated the rest to 2008 R2 with clean VMs

[Duke]

It's funny, I read all the details of not doing DC's and had a company come in and do the migration and setup of our VM environment. They happily P2V'd the DC which was also the main file server, antivirus server and other bits and pieces (legacy so is gradually being reduced) and just did it even with me offering to demote it and it worked fine, so I guess YMMV but with things like that I left it in their hands knowing I had a backup but if something went wrong, it wouldn't be me spending time resolving it. (I wouldn't have risked it myself)

 

Was it just a single DC? If so you can normally do it and get away with it. You can also generally snapshot and restore a single DC, although I don't think either are best practice per se.

 

The issue comes about when you have multiple DCs, P2V or restore from snapshot one of them, and it starts to sync up with the other DCs with old updates. DCs have an 'Update Sequence Number' that allows them to keep their databases in sync, and when you roll back one DC to an old USN it really screws with the others.

 

A single DC normally isn't recommended unless you only have a very small site, but for backup and restore purposes it can end up making your life a lot easier.

 

Chris

[chazzy2501]

I p2v'd everything I could. I figured it was a good time to think about rebuilding but if I had the original servers P2v'd then I had more flexability when it came to altering things. as for the 2 DCs issues I just turned one off whilst I p2v'd the other one. Then p2v'd the second one. No issues. Still I never did get around to rebuilding those servers

[teejay]

This is one reason why I'm seriously looking at moving our DC's to Server 2012 as this fully supports snapshots/clones as a domain controller, VMWare 5 with the latest service pack and 5.1 both support this. Maybe worth looking at if you are on a Schools/EES agreement as it would ease your pain later ;-)

[Duke]

as for the 2 DCs issues I just turned one off whilst I p2v'd the other one. Then p2v'd the second one. No issues.

 

Lol! That's one way of doing it I guess!

[Cache]

No it wasn't a single DC, it was one of 2 (only one was virtualised) and it was kept running throughout (hence my concern and then adamence that I wouldn't be fixing it if it screwed up)

 

I did do a lot of checking to make sure that everythign was working the following day and we've been running since the summer without issue (thankfully)