Migrate and attach existing disk of a VM to another VM on remote machine

Question

There are 2 physical servers with Proxmox (Proxmox-ve 4.2) installed on them, each one handles few VMs and containers. These servers are (almost) completely isolated and there is no cluster/shared storage/additional storage, etc. between them.

A VM has been setup and configured it's OS and application(s) on proxmox#1 but it should be moved to proxmox#2. In prior versions of Proxmox, it was as easy as moving the VM's disk image to another server using rsync or scp. But in recent versions of Proxmox, storage for storing VM's disk are completely separated with parent host using lvmthin and there is a logical volume for every single VM, state, snapshot, etc.

As I do not want to install OS and setup applications, how can I migrate existing VM disk image from proxmox#1 to proxmox#2 and attach it to a VM just recently created as the main disk?

Answer 1

I found a tricky way and it's as easy as you can not believe.

On source (proxmox #1):

First, you have to use "Move disk" in order to get access to VM's disk as a raw or qcow2 file. Using web interface, go to Datacenter --> Storage and select local. Click Editand in Content drop down, select Disk image ("Iso image", "Container template" and "VZDump backup file" are already selected). Put "Max Backups" 0 or 1 if OK button is disabled. Then select your VM on the left, go to Hardware tab, select Hard Disk and click Move disk. On Target Storage of the pop-up box, select local and choose appropriate Format. "QEMU image format(qcow2)" is OK in this case. You can check "Delete source" or delete it manually later (this is suggested). Finally click Move disk and after few minutes, your VM disk is ready. It's dumped in /var/lib/vz/images/VMID/. When you are done, unselect Disk image from Datacenter --> Storage, select local and click OK.

On destination (proxmox #2):

Using web interface, go to Datacenter --> Storage and select local. Click Editand in Content drop down, select Disk image ("Iso image", "Container template" and "VZDump backup file" are already selected). Put "Max Backups" 0 or 1 if OK button is disabled. Then create a VM with the same specifications you had on source server, but select local from drop down in Storage section of Hard Disk tab. Do not turn on the machine. Go to /var/lib/vz/images/VMID/ and remove vm-VMID-disk-1.qcow2. Move image dumped on source server (proxmox #1) to destination server (proxmox #2) '/var/lib/vz/images/VMID/' with vm-VMID-disk-1.qcow2 name using rsync or similar tools.

Select your VM on the left, go to Hardware tab, select Hard Disk and click Move disk. On Target Storage of the pop-up box, select local-lvm and choose appropriate Format. When you are done, unselect Disk image from Datacenter --> Storage, select local and finally click OK.

Turn on the VM!