Question about user storage and vSphere (or Hyper-V)

if you have a virtualized environment and are using a SAN for all storage, how do users save docs etc to their home directories? in a "regular" client/server environment, as admin, you can set it up via gpo so they can just auto save to their home dir, but thats on a physical server. how do you set something up if the storage is on an iSCSI network? isnt that usually on a completely different subnet?
Comments
That is just one scenario, though. You may not want users saving files inside VMs. For example you can enable folder redirection, so files will be saved on a network share somewhere (for example, a share you create on another VM, which may or may not reside on SAN storage) instead of locally. Or use roaming profiles, so data is stored locally at first, but later copied to a network share.
MCSA 2003, LFCS, LFCE (expired), VCP6-DCV
i guess im just wondering how this process is "invisible" to the end users. i mean, if i can get them to understand the concept of locking their machine when they get up, im gonna have a tough time selling to them the next time they want to save a file it goes to 2020-01.com.companydomain:iscsi1 instead on "tdean".
EDIT: one more thing, the "NAS" or storage is a separate machine, while the datastores/vms are typically spread across a couple different ESXi/Hyper-V servers?
VMs can be stored on SAN/NAS space (i.e. shared storage), and run on various servers. If they are stored on a particular host, it can only run on that particular host.
MCSA 2003, LFCS, LFCE (expired), VCP6-DCV