Unable to Migrate VMs from LVM-Thin to a New Node

[Kratus]

Hello everyone,


I have a node that is almost out of storage, so I added an additional node to the cluster to offload some VMs. However, I am unable to migrate them because they are stored in LVM-Thin, which does not support direct migration.


I attempted to set up a shared storage on the new node using ZFS, but it was unsuccessful. I also tried using Proxmox Datacenter Manager, but I couldn't make it work.


At this point, I urgently need a solution to move my VMs before the storage on my primary node becomes completely saturated.


Any ideas or assistance would be greatly appreciated!


Thks

 

[Kratus]

Hi all,

Following up on a previous post, I understand that LVM-thin is not ideal for live migration in Proxmox, and I'm aware of its limitations. My current setup hosts several critical VMs that require minimal downtime, so a full shutdown or offline migration isn't a great option.

I considered backing up and restoring the VMs to a separate SSD, but that approach is not feasible due to several constraints. The new node I built was intended to replace the overloaded one, and I assumed that once the cluster was properly integrated, I’d be able to live-migrate VMs without major issues.

Unfortunately, that's not happening. My main host is already under heavy disk I/O load and lacks enough local or external storage to spare. However, the network infrastructure between the nodes is solid — both have 10Gbps SFP links.

Now I'm thinking about switching the main node's storage backend from LVM to ZFS to allow live migration and potentially enable replication in the future. But I’m not sure how disruptive that would be to the existing VMs or how to plan that transition without downtime.

Any suggestions on how to safely transition from LVM to ZFS in a production environment with limited resources? Or alternative strategies to enable live migration in this scenario?

Appreciate any input.

 

[Kratus]

I successfully migrated a VM (ID 1010) from one node (intranet) to another (intranetpanda) using CLI with local storage.


Since the source node used local-lvm (LVM-Thin) and the destination node had a different storage name (Storage-A), I used the following command:


qm migrate 1010 intranetpanda --online --with-local-disks --targetstorage Storage-A

 

[louie1961]

For future reference, one easy way to do it is to use NFS or SMB storage. You can back up your VM to the NFS then restore it on the new node. Its not a "live" migration, but has always worked flawlessly for me.