I need to transfer over 1tb of data from a share on a ext3 file system that our corporate office uses. The share contains files with different owners and groups and needs to be copied over maintaining these permissions.
After experimenting with this, I have found that the best way to achieve this is to mount the SAMBA shares in Windows Server, and use Robocopy to sync the files. It will do a mirror copy if you want it to. It's a very robust file copy tool in windows (later versions) I knew nothing about prior to today.
In fact, it has a /SECFIX option that will fix security information on files already copied. I am testing this functionality against a rsync copy made of the ext3 fs we are moving. With any luck, before days end I will have a complete up to date copy of the corporate share including correct ownership and permissions!