After upgrading vCenter to 7.0 u3h configuring backup fails with error "Access to backup server is denied. Check your credentials"
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After upgrading vCenter to 7.0 u3h configuring backup fails with error "Access to backup server is denied. Check your credentials"

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Article ID: 314662

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Updated On:

Products

VMware Cloud Foundation VMware vCenter Server

Issue/Introduction

Symptoms:

  • Post upgrading VC to 7.0 u3h, when trying to configure the backup on VAMI it fails with the error "Access to backup server is denied. Check your credentials"

  •  Checked applmgmt.log

2023-02-24T00:00:03 AM AEDT [3096]INFO:plugins.SMBClientStorageIOLib:Running Command: ['/usr/bin/smbclient', '//backupserver.vsphere.local/backup_share/', '-A', '/dev/shm/smbCredentialFile8begk_do', '--send-bu
ffer', '100M', '-c', 'cd files/backup/vxrail/vCenter/vcsa1.vsphere.local/; ls']
2023-02-24T00:00:04 AM AEDT [3096]ERROR:plugins.SMBClientStorageIOLib:Command failed with error: NT_STATUS_LOGON_FAILURE
2023-02-24T00:00:04 AM AEDT [3096]ERROR:vmware.appliance.backup_restore.archive_impl:Failed to enumerate archive info. Url smb://backupserver.vsphere.local/backup_share/files/backup/vxrail. Err [Failure instance: Traceback: <class 'plugins.StorageIOErrorsLib.PluginError'>: Plugin error occurred. ErrCode: 1, Args: ()
/usr/lib/python3.7/threading.py:926:_bootstrap_inner
/usr/lib/python3.7/threading.py:870:run
/usr/lib/python3.7/site-packages/twisted/_threads/_threadworker.py:46:work
/usr/lib/python3.7/site-packages/twisted/_threads/_team.py:190:doWork
  • Backup using IP fails with same UI error and NT_STATUS_LOGON_FAILURE in the applmgmt.log




Environment

VMware vCenter Server 7.0.3

Cause

Starting vCenter 7.0 Update 3h build 20395099, the backup architecture has been changed to 'smbclient' from 'cifs' . Limitation of samba client being kerberos DNS TXT packets that are needed for kerberos authentication are not supported.
This causes specific failure in environments where Domain-based DFS namespace is used for the target backup location.

Resolution

Configure VCSA to backup by using the DFS UNC path instead of the DFS referral path.

For example:
All VCSAs are configured to use backup path
//backup_server.vsphere.local/imsshare/files/backup/vxrail which is a DFS path that points to a cluster of DFS shares which has been working fine until the the VCs are upgraded to 7.0.3.01000.

Change the backup path to the direct UNC path i.e.
//server01.vsphere.local/server01/Files/Backup/VxRail the VCSA backup will complete successfully.