Yes, it is possible to erasure files and folders in SAN storage, as long as Blancco File Eraser can access the file structure on the SAN from the host PC or server where Blancco File Eraser is installed.

Related articles:

http://support.blancco.com/index.php?/Knowledgebase/Article/View/592/62/how-can-i-use-blancco-file-to-securely-erase-files-and-folders-from-my-corporate-it-infrastructure