VMware Consolidated Backup fails with the error: No path to device

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• Backing up a virtual machine using VMware Consolidated Backup (VCB) over the SAN fails
• You see these errors:
  
  • No path to device
    
    Note: This error may occur even if the LUN on which the virtual machine resides has been properly presented to the VCB proxy or if other virtual machines on the same LUN can be backed up successfully.
    
    
  • No path to device LVID:49243c81-b42132d2-f31b-0010183959f6/49243c80-20484305-2ab1-0010183959f6/1 found.
    
    

• The output of vcbmounter.exe shows the error:
  
  No path to device NAA:6000e5600009990000000000000002f2536f6d70656c found.
  [2008-07-03 10:46:12.650 'BlockList' 4216 error]
  [2008-07-03 10:46:13.056 'vcbMounter' 4216 error] Error: Failed to open the disk
  : Cannot access a SAN/iSCSI LUN backing this virtual disk. (Hint: Option "-m ndb
  " swtiches vcbMounter to network base disk access if this is what you want.)

Environment

VMware Consolidated Backup 1.1.x
VMware Consolidated Backup 1.0.x
VMware Consolidated Backup 1.5.x

Resolution

This issue may occur if:

• The VMware Consolidated Backup proxy has not properly presented the LUNs that contain the VMFS volumes which house the virtual machines you want to back up. To conduct backups via the storage network (-m san switch) you must present the VMFS LUNs to the VCB Proxy. For more information, see Setting Up a VCB Proxy in the Virtual Machine Backup Guide for your VMware product and version. For more information on LUN presentation, see the SAN Configuration Guide for your VMware product and version and your storage array vendor documentation.
  
• The VMware Consolidated Backup proxy has paths to only one out of multiple storage controllers and the LUN has trespassed to a storage controller which the VCB proxy is not configured to see in the storage network. For more information on LUN presentation, see the SAN Configuration Guide for your VMware product and version and your storage array vendor documentation.
  
• The virtual machine experiencing the symptoms has raw device mappings (RDMs) which point to LUN(s) that have not been presented to the VCB proxy server. To resolve this issue, ensure that the virtual machine does not have any RDMs which point to LUNs that have not been presented to the VCB proxy server. If the virtual machine does have RDMs, perform one of these options:
  • Change the RDMs to independents disks so they will not be backed up.
  • Present the LUNs to the VCB proxy server.
    
    Note: This procedure is dependent on your storage array. Consult your vendor documentation for more information.