thinQmaster Virtual testing partner Adaptive practice exams that find your weak spots and drill them. Every answer explained. From $69
Enroll

thinQmaster

Find your exam

Five questions free, before you decide.

Step 1 · choose a vendor

In one of our camps? Your practice exams come with the tuition — they are on your study page already.

Systems & Data Center · Foundational

/dev Directory

The Linux directory containing device files that represent hardware and pseudo-devices, such as disks, terminals and /dev/null.

Definition

Device files in /dev are either block devices (buffered, random access, e.g. /dev/sda, /dev/nvme0n1) or character devices (unbuffered streams, e.g. /dev/tty). Modern systems populate /dev dynamically using udev.

Example

Sending unwanted output to /dev/null discards it: command 2>/dev/null.

Exam tip

Know common names: /dev/sdX for SCSI/SATA disks, /dev/nvmeXnY for NVMe namespaces, and /dev/null, /dev/zero and /dev/random as pseudo-devices.

Related terms