VM Migration in Proxmox (Complete Guide)

VM Migration in Proxmox (Complete Guide)

This article explains how to migrate virtual machines (VMs in Proxmox) using GUI and CLI methods, covering clustered, standalone, and offline/manual migration scenarios.

It is suitable for:

• System administrators

• IT / security engineers

• Lab and production environments

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1. What Is VM Migration in Proxmox?

VM migration is the process of moving a virtual machine from one Proxmox host to another. Depending on the setup, migration can be:

• Live migration (VM keeps running)

• Offline migration (VM is powered off)

• Manual migration (no cluster / no shared storage)

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2. Types of Proxmox VM Migration

Migration Type	Requires Cluster	Requires Shared Storage	Downtime
Live Migration	Yes	Yes	None
Offline Migration	Yes	Optional	Yes
Backup & Restore	No	No	Yes
Manual Disk Migration	No	No	Yes

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3. Live Migration (Cluster + Shared Storage)

Requirements

• Proxmox cluster configured

• Shared storage (NFS, iSCSI, Ceph, ZFS over iSCSI)

• Same CPU architecture

• Same Proxmox version (recommended)

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GUI Method (Live Migration)

1. Select the VM

2. Click Migrate

3. Choose the target node

4. Enable Online migration

5. Click Migrate

The VM continues running during migration.

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CLI Method (Live Migration)

qm migrate 100 node2 --online

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4. Offline Migration (Cluster, No Shared Storage)

This method shuts down the VM and copies disks over the network.

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GUI Method (Offline Migration)

1. Shut down the VM

2. Select Migrate

3. Choose the target node

4. Disable Online migration

5. Start migration

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CLI Method (Offline Migration)

qm shutdown 100
qm migrate 100 node2

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5. VM Migration Using Backup & Restore (Recommended for Standalone Hosts)

This is the safest and cleanest method when hosts are not clustered.

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Step 1: Create a VM Backup (Source Host)

GUI

1. Select VM → Backup

2. Choose storage

3. Mode: Stop (recommended)

4. Compression: zstd

5. Click Backup

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CLI

vzdump 100 --mode stop --compress zstd

Backups are stored in:

/var/lib/vz/dump/

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Step 2: Transfer Backup to Destination Host

scp /var/lib/vz/dump/vzdump-qemu-100-*.zst root@node2:/var/lib/vz/dump/

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Step 3: Restore VM on Destination Host

GUI

1. Go to Datacenter → Storage → local → Backups

2. Select backup file

3. Click Restore

4. Choose new VMID or keep original

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CLI

qmrestore /var/lib/vz/dump/vzdump-qemu-100-*.zst 100

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6. Manual VM Migration (No Cluster, No Backup)

Used when backup is not possible or disk-level access is required.

High-Level Process

LVM-thin disk → qcow2 file → copy → LVM-thin disk

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GUI Method (Manual Disk Migration)

Source Host

1. Enable Disk image on local storage

2. VM → Hardware → Disk → Move Disk

3. Target: local, Format: qcow2

Disk appears at:

/var/lib/vz/images/VMID/

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Destination Host

1. Create VM with same configuration

2. Delete auto-created disk

3. Copy qcow2 file using rsync

4. VM → Hardware → Move Disk → local-lvm

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CLI Method (Manual Disk Migration)

# export disk
qemu-img convert /dev/pve/vm-100-disk-0 vm-100-disk-0.qcow2

# copy disk
scp vm-100-disk-0.qcow2 root@node2:/var/lib/vz/images/100/

# import disk
qm importdisk 100 vm-100-disk-0.qcow2 local-lvm

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7. Common Migration Issues & Fixes

Issue	Cause	Solution
VM won’t boot	BIOS mismatch	Match UEFI / SeaBIOS
Network missing	New MAC	Update DHCP / static config
Windows disk missing	No VirtIO	Install VirtIO drivers
Slow migration	No compression	Use zstd

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8. Best Practices

✔ Prefer backup & restore for standalone hosts ✔ Use live migration only with shared storage ✔ Match CPU type between nodes ✔ Always test migration in staging ✔ Keep Proxmox versions aligned

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9. Migration Method Decision Guide

Scenario	Best Method
Production cluster	Live migration
Cluster without shared storage	Offline migration
Standalone hosts	Backup & restore
Disk-level recovery	Manual migration

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10. Summary

Proxmox provides flexible VM migration options:

• Live migration for zero downtime

• Offline migration for simple clusters

• Backup & restore for standalone nodes

• Manual migration for advanced scenarios

Choosing the correct method ensures data safety, minimal downtime, and predictable results.

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End of article

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REFERENCES

• https://www.bdrshield.com/blog/proxmox-vm-migration-a-step-by-step-guide-for-offline-migration-part-13/