Optional sequence 2 : creating a file persistently under /dev/
Scenario: you want to make sure the /dev/myusbdisk filename is available after a reboot and can be used to mount a usb device
Deliverable : A system that provides /dev/myusbdisk automatically after a reboot.
System setup system running in runlevel 5
Instructions
1, modify the udev subsystem in such a way that /dev/myusbdisk gets automatically create at boot time.
2, reboot the system
Plug a sub key to your system and verify that you now have a file named /dev/myusbdiskk
3, MANDATORY CLEANUP:remove the file you have created under /etc/udev/rules.d/and uplug the usb device.

Optional sequence 2 solutions
1,Modify the udev subsystem in such a way that /dev/myusbdisk gets automaticall created at boot time
Create a file named /etc/udev/rules.d/99-usb.rules and insert the following statement in it :
KERNEL==”sdb1”,NAME=”myusbdisk”
Note system with ide haddrives use sda for the first USB　disk.
2, reboot he system
Init 6
Plug a usb key to your system and verify that you now have a file named /dev/myusbdisk
ls –l /dev/myusbdisk
3, MANDATORY CLEANUP:remove the file you have created under /etc/udev/rules.d/ and uplug the USB device:
Rm /etc/udev/rules.d/99-usb.rules