Proxmox 4.1 and 4.2 hosts in the same cluster

[NxwJfm]

Hello.

I've been happily running a 6 host Proxmox 4.1 cluster for a few months now, and I'm going to join 2 new hosts to the cluster soon.
Since the kernel included in the Proxmox 4.1 iso is buggy with our iSCSI setup, I need to do an upgrade after installing the host, which will then be upgraded to 4.2. So my question is it it possible to have both 4.1 and 4.2 hosts in the same cluster? As far as I could see in the forum it seems to be ok, but better safe than sorry

Thanks in advance!

 

[dcsapak]

while technically possible, it is not recommended (because there may be compatibilty issues)
but why do you not upgrade your existing nodes?

 

[NxwJfm]

Hello, thanks for the reply

I don't upgrade them because I don't know for sure I can mix 4.1 and 4.2 hosts

I can't afford any downtime, so my VMs have to stay up whenever I upgrade. I can of course migrate all of the ones running on one host onto another one, upgrade the now empty host, and then migrate them all back, but I still temporarily would have a cluster of 4.1 and 4.2 hosts.
If there are any option to do all this without any downtime for the VMs themselves, I'll be happy to upgrade everything of course.

 

[dcsapak]

no this should not be problem,
one caveat though: we recently introduced a change in how live migrations work internally, so that new -> old does not work out of the box (but with a workaround)
but in your scenario this should not be necessary since you only ever migrate from old->old or old->new

 

[NxwJfm]

Alright, sounds good. So you'd say I first upgrade my current hosts to 4.2, then introduce the 2 new ones, or any order will do?

 

[dcsapak]

it should not matter in your case

 

[NxwJfm]

Alright sounds good, thanks for your help!