RE: Big VMWare disk import experience/recommendation

[Kyle Sexson <ksexson@cobaltcattle.com>]

Have you looked into he 'Minimal Downtime' move option? https://pve.proxmox.com/wiki/Migrate_to_Proxmox_VE#Attach_Disk_&_Move_Disk_(minimal_downtime)

The short description is you have VMWare move the vmdk files to shared storage with PVE and then import the disks from the shared storage.  This can avoid the speed limitations with the VMWare API used by the automated process

-----Original Message-----
From: Eneko Lacunza <elacunza@binovo.es> 
Sent: Wednesday, March 4, 2026 9:58 AM
To: pve-user@lists.proxmox.com
Subject: Big VMWare disk import experience/recommendation

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Hello all,

We are planning a migration of about 65 VMs from a VMWare v8 cluster to PVE. There is a mixture of Debian, Ubuntu and Windows machines there.

We have done that before, but during the last migration a month ago (unrelated customer) we had performance issues importing/converting the disks (WUI wizard). Some of the issues we could fix removing VM snapshots from VMWare, but others (with the biggest disks, about 3,5T) prevailed, even after checking for snapshots (no snapshots present) and trying to flatten the disk image. Those were file servers and we had to fail back to copying disk contents with robocopy, and fippling VMs to minimize downtime; a procedure that has its issues....

In the new migration, we have a pair of VMs with 12TB disks, and one with 35TB. We're afraid to suffer again the disk copy/convert performance issues.

Any recommendation would be much appreciated.

Regards

Eneko Lacunza
Zuzendari teknikoa | Director técnico
Binovo IT Human Project

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