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The SAN Transport Mode is a way to implement a LAN-free backup solution when the backup server is a physical machine and have a direct access to the VMFS datastores. This method was first provided by the VCB Framework and then ported to the vStorage API related to backup and data protection.

In order to use this method in the proper way, some configurations and considerations are required:

  • SAN visibility: the backup server (or the “proxy” machine in a Veeam Backup 6 environment) need to have an access to the VMFS datastores at least with a read permission. That means, for a FC SAN, make a correct zoning and masking of your system (similar as the hosts).
  • Disable Automount: to avoid disk re-signature the automount feature of Windows must be disabled (with diskpart utility). See also this thread on the VMware Community for possible issue.
  • Compatibility: for Veeam Backup 5 there is a specific fix to support the new VMFS5 datastores, for Veaam Backup 6 a specific fix could be required for some type of storage.
  • Multipath: for FC SAN and a active-passive storage the multi-path utility is needed in order to avoid multiple disks version (with the risk to use the off-line disk instead of the active one). For iSCSI SAN the Microsoft iSCSI initiator can handle the multiple paths and avoid this issues. But in both cases a vendor specific multi-path driver and utility are needed in order to gain maximum performance and bandwidth.
  • iSCSI tuning: see this interesting pages with some useful notes for iSCSI SAN.

Note that SAN mode cannot be used if the backup server (or the proxy server, in Veeam 6) isn’t a physical machine. If it is a virtual machine, then the Hot-Add or the NBD mode must be used instead.


Virtualization, Cloud and Storage Architect. Tech Field delegate. VMUG IT Co-Founder and board member. VMware VMTN Moderator and vExpert 2010-24. Dell TechCenter Rockstar 2014-15. Microsoft MVP 2014-16. Veeam Vanguard 2015-23. Nutanix NTC 2014-20. Several certifications including: VCDX-DCV, VCP-DCV/DT/Cloud, VCAP-DCA/DCD/CIA/CID/DTA/DTD, MCSA, MCSE, MCITP, CCA, NPP.