Forcing VMWare Access Host

This may be documented somewhere so let me apologize if it is, I may not have entered the right magical phrase into the google machine to get the right results.

My environment is made up of 3 Netbackup servers (7.5.0.6); 1 Linux master/media server, 1 Windows media server and 1 Linux media server. The only host with SAN access to the vm datastore is the Windows media server and is specified in the master server properties --> VMWare Access Host section. On the policy for the vm backups I have selected to use SAN and to use this windows media server but with all of these properties set it will still try to use the other 2 media servers if this one is busy. The resulting error when attempts are made from the wrong media server is status 59. Is there a way to keep this from happening?

I did find this note in the Symantec Netbackup for VMWare Administrators Guide - Page 52 but wasn't sure if it was my problem.

http://kbdownload.symantec.com/resources/sites/BUSINESS/content/live/DOCUMENTATION/5000/DOC5162/en_US/NetBackup7.5_AdminGuide_VMware.pdf?__gda__=1403715413_db0c4be2385bd76b2993d04ce44a2b11

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Note:

The storage unit that is specified in the policy must be unique to

your Windows media servers. If the storage unit is also available on a UNIX

media server, the snapshot cannot succeed.

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We are using SLPs that point to a single storage pool.

Thanks in advance.