Download this: http://blogs.sun.com/danielc/resource/usbdrived

chmod +x  
./usbdrived install

Using it with Windows Connector:
The Argument is: -r disk:USBDRVS=$HOME/USBDRVS 192.168.1.1 - where you should replace the IP Adress with your Terminal Server

Notes:

• After adding a Drive, it can take up nearly a Minute until it comes “online”!
• The SunRay 1 use USB 1.1 - so that thing is quite slowly!

Troubleshooting:

• Can you see usbdrived running in your Solaris session? (ps -ef | grep usbdrived)
• Can you see a file called “Attaching USB Drives to your Sun Ray README.txt” on your Solaris desktop?
• Did you install it properly? If so, can you see and what permissions does this have:
  /usr/dt/config/Xsession.d/1350.usbdrived (It should be executable by everybody, something like rwxr-xr-x)
• When you plug in a USB drive, does it mount in /tmp/SUNWut/mnt/<username> under Solaris?
• Under Windows, can you see in “My Computer” a Network drive (In “Others”) called “USBDRVS” and is there a file within that explains usage?
• Have you hit refresh in file manager when looking at your USBDRVS mount?
• Most important and useful of all: Do any mounts show up if on a Solaris Sun Ray session you issue: /opt/SUNWut/bin/utdiskadm -l

Taken from: http://blogs.sun.com/danielc/entry/a_usb_drive_daemon_for1