vCenter Server Backup – Failed to create backup directory on Backup Server

byArron King 08.15.2022 VCSA

I noticed an alarm in vCenter that indicated the vCenter Server Appliance (VCSA) was having trouble backing up.  I logged into the VCSA Appliance Management interface (vCenter URL with :5480) to investigate.  When I logged in, I found the following error:

Failed to create backup directory on Backup Server

vcsa backup - failed to create directory

Thinking there was something wrong on my SFTP server, I checked the username and password, file system permissions; but could find nothing wrong. I connected to the VCSA using root on SSH, and checked the log file at /var/log/vmware/applmgmt/backup.log.  This provided some additional detail on the issue and showed the backup process was unable to authenticate to the SFTP server.

VCSA backup.log - failed to authenticate

 

 

 

I tried the SFTP command manually and found the core of the issue:

VCSA - SFTP command requires acceptance of SSH key

 

 

 

For some reason, the SSH key has changed and needs to be updated in the local SSH Known Hosts file.  Once I accepted this new key, the backup was able to complete successfully.

VCSA Backup Completed

 

 

 

 

I am not sure what would have changed the SSH key.  The only thing I can think of is that I had updated vCenter from 7.0 U3f to 7.0 U3g recently.  I have verified the host is correct.

vToolbelt - July 2022

vToolbelt - August 2022

4 thoughts on “vCenter Server Backup – Failed to create backup directory on Backup Server”

  1. Preebeka

    Thank you. It really helped me today.

    Reply
    • Web Master

      Thank your for visiting. I am glad it was helpful!

      Reply
  2. kedar

    I have tried running above commands, accepted new SSH keys but still getting same error

    Reply
    • Web Master

      While the steps I listed solved my problem, there could be other issues that are going on. Here are a few more ideas on what you can check:

      • Walk through the SFTP process manually from a shell on your vCenter including uploading a file. This can help identify issues with path and permissions on your backup server.
      • Make sure your vCenter is fully patched. I have seen a few issues with some releases that have been resolved by applying a patch. Reviewing the release notes for subsequent versions may be helpful
      • If none of these help, I would recommend opening a support request with VMware Global Support. They will be able to review the issue in depth and help get it resolved
      Reply
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