Although "VMVSTORTRANSPORT SAN" is set in the datamovers options file, the backup uses NBD.
Backup uses NBD transport
VMware vCenter 'SSL.VERSION' setting is set to TLSv1.
vCenter 5.1 or 5.5.
Diagnosing the problem
A Tivoli Storage Manager client trace will show the following:
Cannot use advanced transport modes for VCENTER/moRef=vm-12345/snapshot-6789: Other error encountered: SSL Exception: error:14094410:SSL routines:SSL3_READ_BYTES:sslv3 alert handshake failure.
Resolving the problem
The SSL.VERSION parameter needs to either be set to 'ALL', or if TLS is a requirement, then the Tivoli Storage Manager client (datamover) must be upgraded to version 7.1.2.x. This version of client includes VDDK version 6.0 which has added support for TLS.