#1 Global Leader in Data Resilience

After Upgrade to Veeam Backup & Replication 12.1, Backup of Linux VM Fails With: "Failed to check fingerprint"

KB ID: 4524
Product: Veeam Backup & Replication | 12.1
Published: 2023-12-12
Last Modified: 2023-12-12
mailbox
Get weekly article updates
By subscribing, you are agreeing to have your personal information managed in accordance with the terms of Veeam's Privacy Notice.

Cheers for trusting us with the spot in your mailbox!

Now you’re less likely to miss what’s been brewing in our knowledge base with this weekly digest

error icon

Oops! Something went wrong.

Please, try again later.

Challenge

After upgrading to Veeam Backup & Replication 12.1, Backup jobs for Linux VMs that operated successfully before the upgrade now fail with:

Unable to connect to guest OS for guess process. Failed to check fingerprint.
Error

Cause

During the upgrade to Veeam Backup & Replication 12.1, the format used to store SSH fingerprints for Linux machines is updated. However, for environments where the configuration database was stored in a Microsoft SQL instance running SQL 2022 or 2019, the conversion process fails to correctly process blank current_fingerprint values in the Backup.Model.HostSshFingerprint table. Those blank values are replaced with NULL, which is unexpected by Veeam Backup & Replication.

Solution

To resolve this issue, manual fingerprint validation must be performed for each machine that failed with the error.

  1. In the Main Menu (≡), click Options.
  2. Switch to the Security tab.
  3. In the section labeled "Linux hosts authentication," change the setting to:
    Add unknown hosts to the list manually (more secure)
  4. Rerun the job(s) that failed.
  5. Validate SSH Fingerprints and Trust entries within the Untrusted node in the Inventory view.
  6. Run the jobs that failed once more.
  7. After all jobs have returned to an operational state, you may return the Linux host authentication setting to Add all discovered hosts to the list automatically.
To submit feedback regarding this article, please click this link: Send Article Feedback
To report a typo on this page, highlight the typo with your mouse and press CTRL + Enter.

Spelling error in text

Thank you!

Thank you!

Your feedback has been received and will be reviewed.

Oops! Something went wrong.

Please, try again later.

You have selected too large block!

Please try select less.

KB Feedback/Suggestion

This form is only for KB Feedback/Suggestions, if you need help with the software open a support case

Veeam Backup & Replication
Veeam Data Cloud for Microsoft 365
Veeam Data Cloud for Microsoft Entra ID
Veeam Data Cloud for Salesforce
Veeam Data Cloud for Microsoft Azure
Veeam Data Cloud Vault
Veeam Backup for Microsoft 365
Veeam Backup for Microsoft Entra ID
Veeam Backup for Salesforce
Veeam ONE
Veeam Service Provider Console
Veeam Agent for Microsoft Windows
Veeam Agent for Linux
Veeam Backup for Nutanix AHV
Veeam Backup for AWS
Veeam Backup for Microsoft Azure
Veeam Backup for Google Cloud
Veeam Backup for Oracle Linux Virtualization Manager and Red Hat Virtualization
Veeam Management Pack for Microsoft System Center
Veeam Recovery Orchestrator
Veeam Agent for Mac
Veeam Agent for IBM AIX
Veeam Agent for Oracle Solaris
Veeam Cloud Connect
Veeam Kasten for Kubernetes
By submitting, you are agreeing to have your personal information managed in accordance with the terms of Veeam's Privacy Notice.
Verify your email to continue your product download
We've sent a verification code to:
  • Incorrect verification code. Please try again.
An email with a verification code was just sent to
Didn't receive the code? Click to resend in sec
Didn't receive the code? Click to resend
Thank you!

Thank you!

Your feedback has been received and will be reviewed.

error icon

Oops! Something went wrong.

Please, try again later.