Linux - /dev                                 Home : www.sharetechnote.com

 

 

 

I think one of the most important components but the most confusing/mysterious things in linux would be those in /dev. This directly contains all the devices (device drivers) that can be connected to the computer.

 

/dev/sd - sda, sdb,... sda1, sda2,...

 

if you try 'ls /dev/sd*', you will get all the device list starting with 'sd'. What does sd mean ?

It means 'storage device' and 'sd' originally indicated 'SCSI (Small Computer System Interface)', however, as more and more other types of storage devices, it has become indicate various other devices as well, SATA(Serial AT Attachement) and usb etc.

 

However, if you try 'ls /dev/sd*', you would mostly get 'sda', 'sdb' etc.. what does 'a', 'b' etc stands for ?

It is the order of storage device that the linux finds as example below.

    sda : the first device (in most case, this will indicate the primary harddisk on your computer)

    sdb : the second device

    etc

 

Also you would see a number followed by these device like sda1, sda2 etc. what does this number indicates ?

it indicates the partition number, so sda1, sda2, sdb1 means as follows.

    sda1 : the first partion on the first storage device

    sda2 : the second partion on the first storage device

    sdb1 : the first partion on the second storage device