Okay, I know this sounds silly but I have been doing some research on how to best upgrade from 1.5 XCP to 1.6 XCP. Some folks are using the Rolling Pool Upgrade Wizard in Xen Center had some issues, but nothing too scary here. Since I only have a handful of VMs running on two physical servers (both of which are in the same pool and both using NFS based storage repositories), I wanted to get another opinion on how to best migrate to 1.6.
Here are my thoughts:
Use the Rolling Pool Upgrade Wizard
Pros: Should work with very little work on my part
Cons: I am not sure how it works. Basically do I want to consider another options for DR purposes ( I will explain about this in a minute ).
Use the XCP 1.6 ISO to install 1.6 on each server
Pros: I will have a known image ISO image to work from in case of DR scenario
Cons: Not sure if this will work the way I want it to, but I believe that as long as I save the XCP metadata and the VM images on the shared storage, this should work.
So why I am concerned about a DR scenario. Because a few months ago we found ourselves in this situation when our HA storage solution failed. After 36 hours of down town and some very angry customers, I am looking for an upgrade process that in a DR scenario I will be able to quickly get back up. So my thoughts are that if I can take the XCP 1.6 ISO and put in a server, given that all the other prerequisites are taken care of like processor types, etc…, then I should feel comfortable recovering a failed server. In theory, if I use an XCP 1.6 ISO on all the servers, I have an easily reproducible DR process.
Box fails, put new box in, use ISO, attach to Pool, then start up VMs. If I use the Rolling Pool Upgrade Wizard, I am a little hesitant to say that if the box fails, will a brand new server with the XCP 1.6 ISO be setup the same or close enough to work.
Obviously, I cannot join a 1.6 server to my 1.5 Pool. What I am not sure about is what is the best way to upgrade from 1.5 to 1.6, and which way carries the easiest DR process in the future. What I do not want is conflicts with the kernel and vice versa by doing a Rolling Pool Upgrade versus a fresh install.
Even if I do load 1.6 on one of the servers, I am not sure that I could transition the Pool master to it and I am not sure that doing it this way is advisable.
Does anyone have some thoughts here????
Juan
