Upgrading proxmox cluster from 5.6 to 6


New Member
Sep 17, 2019
Hi everyone,
Im guessing if we can upgrade our proxmox cluster node by node.
We have a 9 nodes cluster and we would like to upgrade like 1 node every day.
Proxmox 5.6 is compatible with other proxmox 6.0 nodes?

Thank you very much.

Best Reggards,

The upgrade from PVE 5.4 (not sure where you have the 5.6 from - there is no such release) to 6.0 is quite well explained on the upgrade page in the wiki: https://pve.proxmox.com/wiki/Upgrade_from_5.x_to_6.0

make sure to read it thoroughly (e.g. you will need to upgrade corosync on all nodes first )

I hope this helps!
Yes sorry it was a mistake.

I have alredy read the wiki but I'm not sure if I can upgrade the nodes 1 by 1 or we have to do a massive upgrade of all nodes at once. We alredy have corosync 3 on all nodes.

Usually you:
* migrate all (important) guests away from the node you want to upgrade
* upgrade the node
* migrate the (important) guests from another node to this node
* upgrade this second node
and so on

As for the timeframe - In general running a cluster of mixed versions for a longer time is nothing that is tested too much - so if you runt into problems you might need to speed up the upgrade.

Apart from that - migration is generally only tested from an older version (5.4) to a newer version (6.0) not the other way around (could still work (with some drawbacks - e.g. offline migration instead of live-migration , but as said not tested too well)

Also make sure to check the pve5to6 script on all nodes before beginning!
my 2 cents after upgrading my cluster from 5.4 to 6, do update fast. Node by node i followed the tutorial for proxmox upgrade as well as ceph.
When i was in a mixed versions, corosync was losing synchronization. I had to stop corosync and restart it in foreground "corosync -f" on all node until the cluster was sane. Only after i stopped one corosync -f and restart pvecluster.


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