Device Name in Linux

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During the installation and use of Linux, you will inevitably be exposed to many device names such as hda1, ttys0, and eth1. Indeed, they are very different from common windows, so you need to know about them first. In Linux, each device must run under its driver control, and the driver is associated with the special files in the/dev directory, although these files are not real files, however, when you select a device or operate a device, the file name is used to represent the device. These device names are named in a regular manner. We will introduce the names of various devices one by one.

1. Drive
In the/dev directory, each drive is represented by a separate device file. Usually the most common is the hard disk, which can be two to four IDE hard disks. This is/dev/hda,/dev/HDB,/dev/HDC, And/dev/HDD. HD indicates the hard disk, and a indicates the first device, "1" in hda1 represents the first hard disk partition of hda, and so on. The SCSI hard disk is/dev/SDA,/dev/SDB, etc. SD is the meaning of the SCSI device. The first SCSI hard disk is/dev/SDA, the first SCSI tape drive is/dev/st0, and the first CD-ROM will be/dev/cd0. In addition, FD is a floppy disk and the device name is/dev/fd0 and/dev/fd1.

Network Device
In Linux, the ethernet card is usually named eth0, eth1, etc. When an Ethernet Card is detected, it is designated as the first available Interface Card Name, usually eth0. HoweverLinux network devices may not be associated with special files in the/dev directory. Do not be surprised if you cannot find them in/dev. You only need to remember what it is and know how to choose it when setting the system.

Serial device
Each physical serial port in Linux has two device files, TTYs and CUA. When a serial card or data card is detected, it is designated as the first available serial device. It is usually named/dev/ttys1 and/dev/cua1. When setting the device that uses the serial port, if it is an input device, you should select/dev/ttys1. If it is an output device, such as a modem, you should select/dev/cua1.

In the new Linux kernel version 2.4.0, there is a new devfs device file system. At the underlying layer, it overrides the methods and channels for user-device interaction, and is the most radical change to the new kernel. However, when the system is used, almost all device names are changed. For example, "/dev/hda" may be located at "/dev/ide0/disk0 ...". This change increases the namespace available for the device and allows system integration between USB and similar devices. Therefore, if you use the 2.4.0 kernel and enable this function, the device name may be different from the one described above.

Device Name in Linux