Date: Jul 08
Product & Version: All NVBU
OS Version: All
Module & Version: VMware 1.0.11 and up
Application version: All ESX Server
When backing up a virtual machine from a VCB proxy, vcbMounter creates a snapshot, but fails backing the data up with the following errors in the log:
Information 2008/07/25 10:43:33 803 Data Plugin VCB [2008-07-25 10:43:33.593 'BlockList' 1500 warning] Could not log out (VIRTUALCENTER:server\user.na...
Information 2008/07/25 10:43:33 803 Data Plugin VCB [2008-07-25 10:43:33.593 'vcbMounter' 1500 error] Error: Failed to open the disk: One LUN could not ...
Information 2008/07/25 10:43:33 803 Data Plugin VCB [2008-07-25 10:43:33.593 'vcbMounter' 1500 error] An error occured, cleaning up...
The VMware plugin uses the vcbMounter utility to create a consistent snapshot in the temporary directory. This volume is the mounted by vcbMounter on the VCB proxy, which tries to read the data locally. In order to do this, the LUN needs to be shared between ESX server and VCB Proxy. It also needs to have the same LUN number on both machines, which is how vcbMounter knows which volume to mount.
Ensure that the volume holding the temporary snapshot from the ESX server is accessible from the VCB proxy, and if it is that it is accessible through an identical LUN number. Otherwise, you will see the above error reported. Check your zoning configuration and LUN masking settings on the SAN switch to ensure that the VCB proxy only sees the disks/LUNs that the ESX server can see, and that there is only one path to the storage on both machines. Otherwise, the VCB proxy might see additional LUNs that result in a different LUN number for the VMware partition on the VCB Proxy.