I wrote the entry about the difficulty that globalSAN doesn't have any command line interfaces. In short, we can't connect / disconnect to / from an iSCSI target by a script. And I found that globalSAN uses Mach API for messaging. But it's very difficult to imply a method to control the globalSAN daemon.
I gave up on connecting and disconnecting by my script and switched to mounting and unmounting when I want. When a Mac is restarted, Mac OS's autofs mounts an iSCSI volume automatically. But as I wrote yesterday, it can destroy the filesystem on the volume where multi-Mac are used. I found the way to prevent autofs from mounting the volume automatically.
$ sudo vifs UUID=01234567-89AB-CDEF-0123-456789ABCDEF none hfs rw,noauto
Now, I can mount and unmount the volume safely with locking system by my script when I desire to do so.