topic Re: need some help regarding the major number of device file in Operating System - Linux

need some help regarding the major number of device file

Rajan_sa — Tue, 15 Feb 2005 05:37:24 GMT

Hi,

Need some help regarding the device files major number in Linux...

1. What decides the major number of a device?
2. Can we configure the device with its major number greater than 99?
3. Can we convert the major number of an existing device to something else?

Re: need some help regarding the major number of device file

Ranjith_5 — Tue, 15 Feb 2005 06:40:37 GMT

Hi Rajan,

Major number refers to the device driver used for a specific device.

This is system defined. You cannot change it. Eg: in HP-UX the major number for character disk device file is 31 and raw deive file is 188. This cannot be changed.

lsdev will give you the major number for all devices on your system.

Minor number refers the physical location of a device.Minor numbers are unique in a system. ie; there cannot be a minor number with the same name.

regards,
Syam

Re: need some help regarding the major number of device file

Mike Stroyan — Wed, 16 Feb 2005 12:05:35 GMT

You can add aliases for module device drivers in /etc/modules.conf . That can use major numbers larger than 99.

char-major-121 drivername