Q. How do I use USB Pen under Solaris UNIX?

A. Solaris does support USB devices including USB pen / key.

You need to use cfgadm command which is SCSI hardware specific commands. USB device emulated as SCSI hot-plug under Solaris
vold is Volume Management daemon to manage CD-ROM and floppy, ZIP/JAZ, USB and DVD-ROM devices. So you need to start/restart this device.

Procedure to mount USB pen

Login as the root user.

Next insert USB pen.

Type cfgadm to see if it detected or not:
# cfgadm
You should see something as follows:

...
...
usb0/2.0 usb-storage connected configured ok
...
....

Now just create a directory called /rmdisk with mkdir command:
# mkdir /rmdisk

Now start vold daemon to pick up USB pen and mount to /rmdisk/rmdisk0
# /etc/init.d/vold start; volcheck
OR restart vold daemon
# /etc/init.d/vold stop
# /etc/init.d/vold start; volcheck

OR just kill and restart (same as above but less typing)
# pkill -HUP vold; volcheck

Task: Access my USB pen under Solaris?

To access your USB pen under /rmdisk/rmdisk0
# cd /rmdisk/rmdisk0
# ls -l

Use cp and other commands to copy files.

Read man pages of vold, volcheck, pkill, cfgadm for more information.
$ man vold
$ man volcheck
$ man pkill
$ man cfgadm