DevOps in Linux — /sys/dev Directory

Deep dive into Linux /sys directory

Note, full mind map is available at: “DevOps in Linux Mind Map”

/sys/dev

What is /sys/dev

In Linux, the /sys/dev directory specifically contains symbolic links to devices, organized by their type (block or char) and their major and minor numbers. Major numbers identify the device driver, while minor numbers identify a particular device handled by that driver.

Here’s an example of /sys/dev directory:

$ tree /sys/dev
/sys/dev
├── block
│   ├── 259:0 -> ../../devices/pci0000:00/0000:00:04.0/nvme/nvme0/nvme0n1
│   ├── 259:1 -> ../../devices/pci0000:00/0000:00:04.0/nvme/nvme0/nvme0n1/nvme0n1p1
│   ├── 259:2 -> ../../devices/pci0000:00/0000:00:04.0/nvme/nvme0/nvme0n1/nvme0n1p128
│   └── 259:3 -> ../../devices/pci0000:00/0000:00:1f.0/nvme/nvme1/nvme1n1
└── char
    ├── 10:1 -> ../../devices/virtual/misc/psaux
    ├── 10:227 -> ../../devices/virtual/misc/mcelog
    ├── 10:228 -> ../../devices/virtual/misc/hpet
    ├── 10:231 -> ../../devices/virtual/misc/snapshot
    ├── 10:235 -> ../../devices/virtual/misc/autofs
    ├── 10:236 -> ../../devices/virtual/misc/device-mapper
    ├── 10:62 -> ../../devices/virtual/misc/cpu_dma_latency
    ├── 10:63 -> ../../devices/virtual/misc/vga_arbiter…