Failed to open VDDK disk

[sinvim]

Hi there,

I am trying to Restore a veeam backup from the repository on my backup server, to a VMWare ESXi server. (Instant Recovery + Quick Migration)

The process starts with publishing the OS from the backup server to ESXI, and after this, you need to finalize the process by Migration to production.

At this step, I am having the following error, and could not find a solution.

15.02.2023 00:10:22 :: Copying snapshot files Error: Failed to open VDDK disk [[Storage] PCW111-Restored/disk0.vmdk] ( is read-only mode - [false] )
Logon attempt with parameters [VC/ESX: [141.64.67.110];Port: 902;Login: [root];VMX Spec: [moref=14];Snapshot mor: [14-snapshot-1];Transports: [nbd];Read Only: [false]] failed because of the following errors:
Failed to open disk for write.
Failed to download disk 'vddkConnSpec>'.
Agent failed to process method {DataTransfer.SyncDisk}.

The Datastore seems to be healthy as some other VMs continue working fine.
Should I put the Host on maintenance mode?


Any help is appreciated, thanks.

[HannesK]

Hello,
That sounds like a technical issue. Please provide a support case ID for this issue, as requested when you click New Topic.
Without case number, the topic will eventually be
deleted by moderators.

Should I put the Host on maintenance mode?

I never heard that this could help

Thank you,
Hannes
PS: support can only help if you upload logs https://www.veeam.com/kb1832

[sinvim]

Hi there,

Case #05877364

[Andreas Neufert]

Please check that DNS is working correctly on the ESXi host, vCenter and all Veeam components.

[bleuze]

Did you ever resolve this. I have the exact same error on a restore. And I know dns is working on all components as I am restoring 2 VMs which were both backed up as part of the same backup job one year ago, both were on the same host previously. Now restoring both to a new host. One has success and the other fails with this error

[veremin]

The case was opened for the free product version (Community Edition) and due to low support staff availability we were unable to process the request.

So kindly reach our support team and create your own ticket.

Thanks!

[K_ndiaye]

Hello everyone

Is there anyone who had to solve this problem because I encounter the same situation?

[PetrM]

Hello,

The error "Failed to open VDDK disk" is quite generic, it just says that the attempt to open a disk for read has failed for some reason. I suggest working with our support team to find out the root cause of the issue in your specific case.

Please open a support case, upload debug logs and share a support case ID for our reference, all posts about technical issues without support case ID will be eventually deleted by forum moderator. See this post for more information about forum rules.

Thanks!

[Moebius]

Reviving an old thread, but I stumbled upon this searching for help for my issue.

I had exactly the same problem when trying and migrating to production an instant-recovered VM. The task kept failing with

18/08/2025 10:29:55 :: Copying snapshot files Error: Failed to open VDDK disk [[*****] ****DCA/****-DC01.vmdk] ( is read-only mode - [false] )
Logon attempt with parameters [VC/ESX: [192.168.*.***];Port: 902;Login: [root];VMX Spec: [moref=14];Snapshot mor: [14-snapshot-1];Transports: [nbd];Read Only: [false]] failed because of the following errors:
Failed to open disk for write.
Failed to download disk 'vddkConnSpec>'.
Agent failed to process method {DataTransfer.SyncDisk}.

In my case the VM are backed up directly from the nodes (the vCenter is not registered with Veeam), and the VCSA prevented the migration to complete. I just shut down the VCSA (didn't have to disconnect the ESXi from the vCenter) and was immediately able to complete the migration.