The size comes from the SCSI read capacity operation which is automatically done when any volume/disk is connected to a server.  This is way before the filesystem layer.    The danger is that someone could come along and format those VMFS volumes with NTFS.  There's no protection at the SAN level for that kind of thing.  With automount disabled it's slightly more difficult but still can occur.  So access to that server should be strictly controlled.  As long as they don't show up as NTFS formatted volumes you should be OK.   One problem is that ESX doesn't routinely re-read the partition table info.  Only on reboots and adding new storage.  (or bring in a snapshot for example)  I have worked with customers who ran for over 6 months with re-partitioned VMFS volumes.  He only lost one VM, so he was very lucky.    Re: Performance.  Make sure that the agent/BUE are running through the SAN subnet, not being routed over  the LAN or other non iSCSI subnet.    If your switch supports both Jumbo Frames and Flowcontrol, then enabling Jumbo Frames might give you an incremental improvement in performance.    In a perfect world, Windows would be able to directly read VMFS volumes.   So you could safely browse and backup / restore VMs or entire VMFS volumes.   There is such a capability in Linux, called "VMFS-TOOLS".  It allows you to 'see' all the VM's and their associated config/log files.   Some folks have used that with ASM/VE to create a more consistent snapshot, mounted it to the Linux server and used the BUE agent to back up the entire volume.  Regards,
Hi all, I am hoping for some clarification.  I have a Dell Equallogic PS400XV SAN and were using a windows server 2008 R2 std with backup EXEC 2010 R3 ith the VMware AVVI angent for backing up our VMware infrastructure. I read that I should disable automount which had been done at the beginning of the project.  Alot of people say that the disks will be shown in Win2008 Server Unknown and not initialized but all my VMware formatted LUNS are visable in the disk management and they even show the size of each LUN / on the windows server.  I get poor backup performance and am trying to rule out everything I can.  Any info on if this is expected or if infact something bad has happened here would be interesting to know. Thanks Sylvester20007
How VMware iSCSI LUNS are Presented to Windows Server 2008 R2 Std