NEC Express5800/ftServer Administrator's Manual page 85

Once you have the name assigned by the udev command (in this case, sd1usb),
you can use udevinfo to find the internal name (in this case, sde):
# udevinfo -q path -n /dev/sd1usb
/block/sde
For more information about the udevinfo command, see udevinfo(8).
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C A U T I O N C A U T I O N
Before unplugging the device, make sure that it is not
being used (the usage count is 0). If a file system is
mounted, unmount it (and make sure the umount
command completes) before unplugging the device. The
umount command flushes any buffered pages back to the
device, so failing to wait for umount to complete can
cause data corruption.
N O T E S
1. An important consequence of the fact that the SCSI
subsystem scans USB devices only on connection is
that simply removing a floppy disk from the floppy
drive or inserting a disk does not cause a rescan. You
must unplug the floppy drive and plug it back in to
cause a rescan.
2. During failovers, access to USB storage devices is
not robust.
3. If an AC switch occurs, some USB devices are not
properly reset and disappear from ftsmaint output.
To reset these devices, you must unplug them and
then plug them back in.
4. When you unplug a device and later plug it back in,
the internal name may change if the SCSI subsystem
has added other devices while it was removed. The
name assigned by the udev command, however,
does not change.
If the active CPU-I/O enclosure fails over to the other enclosure, a mounted USB
disk-drive device may become unusable. If this happens, remove the device from
the system and then insert it back in the system.
USB storage devices are not bootable devices.
USB Storage Devices
Managing Data Storage Devices 6-3