Migrating 6.x Cluster to 7.x

[EagleTG]

Hi everyone,

I read all of the relevant documentation and quite a few forum posts regarding upgrading from 6.x to 7.x. I know the recommended approach is generally to back up the VM, copy it to the new host/cluster, and restore, but I think I settled on a faster/better migration process (for my specific application/need) and wanted to get a sanity check from everyone on the Proxmox Forum.

Current production 6.x cluster has shared storage on a separate ZFS device (FreeNAS). VMs are stored on the ZFS device, Proxmox communicates over iSCSI.

I installed Proxmox 7.4 on two new/spare servers, created a new cluster on those servers, attached those to the same ZFS device via iSCSI.

Since both clusters are seeing the same VM disks on the same storage, I tested a migration by snapshotting an offline VM (just in case), copied the Conf file for this VM to a server on the new cluster (via the /etc/pve/qemu-server folder), the VM appeared and booted properly on the new cluster.

Everything seems awesome with this, and the outage/downtime is very quick for the VM. Shut it down, copy the conf file, boot it up.

Does anyone see a potential issue with this plan? I have manually replicated the entire configuration between the clusters to ensure things are the same, including firewall, etc. I wanted to ask here just as confirmation that I'm not missing anything.

Side note: I then rolled back the migration test by deleting the config file on the new cluster, then reverting to and deleting the storage snapshot.

Thoughts? Thanks!
-Todd

 

[EagleTG]

I just found this article, which seems to confirm that my plan is sound:
https://pve.proxmox.com/wiki/Bypassing_backup_and_restore_when_upgrading

One difference being that I do not need to modify the storage.cfg as I already completed that manually.

 

[spirit]

I read all of the relevant documentation and quite a few forum posts regarding upgrading from 6.x to 7.x. I know the recommended approach is generally to back up the VM, copy it to the new host/cluster, and restore, but I think I settled on a faster/better migration process (for my specific application/need) and wanted to get a sanity check from everyone on the Proxmox Forum.

You don't need to create a new cluster, you have have a cluster with proxmox6 and proxmox7 nodes.

simply upgrade 1 node to proxmox7
live migrate vm from proxmox6 node to proxmox7 node
upgrade second node to proxmox7
live migrate vm from proxmox6 to proxmox7
....
https://pve.proxmox.com/wiki/Upgrade_from_6.x_to_7.0#In-place_upgrade

(I have some old cluster migrated from proxmox4->5->6->7 , without any vm downtime)

 

[EagleTG]

You don't need to create a new cluster, you have have a cluster with proxmox6 and proxmox7 nodes.

simply upgrade 1 node to proxmox7
live migrate vm from proxmox6 node to proxmox7 node
upgrade second node to proxmox7
live migrate vm from proxmox6 to proxmox7
....
https://pve.proxmox.com/wiki/Upgrade_from_6.x_to_7.0#In-place_upgrade

(I have some old cluster migrated from proxmox4->5->6->7 , without any vm downtime)

Ahh, I was hesitant to do this based on some of the forum posts I found regarding mixing 6.x and 7.x versions within the same cluster. There were quite a few posts that seemed to recommend against mixing versions, or maybe more accurately did not necessarily endorse it. I also found this thread which is sort of "on the fence" about it: https://forum.proxmox.com/threads/can-i-mix-promxox-6-and-proxmox-7-in-the-same-cluster.92214/

The documentation at the link provided doesn't provide much comfort surrounding the process to upgrade in a cluster. The one passage here mentions it, but still didn't give me much confidence:
https://pve.proxmox.com/wiki/Upgrade_from_6.x_to_7.0#Move_important_Virtual_Machines_and_Containers

I think I was looking for more clarity in the documentation that mixing 6.x and 7.x in the same cluster is "100% OK for the duration of the migration process" and upon digging through the forums, saw some people saying it works fine, and others that appeared hesitant. Quite a few forum posts seemed to prefer the backup and restore method.

Thanks for your input, I'll give the in-place method a try.

 

[EagleTG]

Update, this post makes it pretty clear that it's important to only mix versions during the upgrade process:
https://forum.proxmox.com/threads/mix-cluster-proxmox-ve-6-and-7-version.92644/

 

[EagleTG]

A bit of a delayed reaction, but for the record, we proceeded exactly like Spirit indicated, and it worked like a charm. Thank you so much for the help. We also moved quickly during the upgrade process to mitigate potential issues with mixing versions within the cluster.