Migrating VMs and OpenVZ containers from Proxmox 3 VE to Proxmox 8 VE

[pidumenk]

Hello forumers,

I am working on the migration from old Proxmox 3 VE to the newest version. As I know one of the simplest ways to move KVM from old environment is using backup and restore options:

vzdump < VM_ID > --dumpdir /var/lib/vz/dump/ --compress gzip --mode stop --node < NODE_NAME >

In case of containers it should be converted from OpenVZ to LXC because OpenVZ isn't available since Proxmox VE 4.x series.

But backup and restore functionality inside of proxmox even when moving to a new host machine restores all original settings and OS version. Surely, OS version is too outdated on it (Debian 7). There is any way how can I restore all staff of VMs to new VMs based on the latest OS version (Debian 12) on my new Proxmox 8 server?

 

[fiona]

Hi,

Hello forumers,

I am working on the migration from old Proxmox 3 VE to the newest version. As I know one of the simplest ways to move KVM from old environment is using backup and restore options:

In case of containers it should be converted from OpenVZ to LXC because OpenVZ isn't available since Proxmox VE 4.x series.

yes. Note also that Proxmox VE >= 7 uses cgroupv2 by default, so you might need to enable legacy cgroup support until you can upgrade the guests to a new enough version: https://pve.proxmox.com/pve-docs/chapter-pct.html#pct_cgroup_compat

But backup and restore functionality inside of proxmox even when moving to a new host machine restores all original settings and OS version. Surely, OS version is too outdated on it (Debian 7). There is any way how can I restore all staff of VMs to new VMs based on the latest OS version (Debian 12) on my new Proxmox 8 server?

You can either upgrade the guests directly (from within the guest) or you'll need to migrate the guest applications to a new guest with a newer OS version. But how that is done highly depends on the concrete application you are using. I'm afraid you'll need to read up for each of them how to do it, so the first variant might be simpler.

 

[pidumenk]

Hi, thanks for your reply. Yes, I was thinking about those 2 ways of migration. Probably, the second way is much better as you can move everything on newer OS version, because upgrading very outdated OS will be a challenge due to old dependencies and not supported repos. Also, you should make upgrades from within the guest OS step by step, it means go to Debian 9, then 10, then 11 and etc.

Well, is this feature of Proxmox backups and restore only helpful when you want to move VMs from one server to another on the present OS version? Otherwise, you should go manually with all steps.

Hi,

yes. Note also that Proxmox VE >= 7 uses cgroupv2 by default, so you might need to enable legacy cgroup support until you can upgrade the guests to a new enough version: https://pve.proxmox.com/pve-docs/chapter-pct.html#pct_cgroup_compat


You can either upgrade the guests directly (from within the guest) or you'll need to migrate the guest applications to a new guest with a newer OS version. But how that is done highly depends on the concrete application you are using. I'm afraid you'll need to read up for each of them how to do it, so the first variant might be simpler.

 

[fiona]

Well, is this feature of Proxmox backups and restore only helful when you want to move VMs from one server to another on the present OS version? Otherwise, you should go manually with all steps.

Of course backup/restore will not modify the guest itself. And since you can run anything inside the guest there can be no general way for Proxmox VE to upgrade the guest itself. That always needs to be done inside the guest.