Disks & Partitions

Disks & Partitioning

Disks appear under /dev: sda, sdb (SATA/SCSI), nvme0n1 (NVMe), vda (virtio). Partitions are numbered: sda1, nvme0n1p1.

Command	Purpose
`lsblk`	Tree of block devices
`blkid`	UUIDs & filesystem types
`fdisk /dev/sda`	Partition (MBR & GPT)
`parted /dev/sda`	Scriptable partitioning (GPT)
`gdisk`	GPT-specific

$ lsblk
NAME   MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
sda      8:0    0  50G  0 disk
├─sda1   8:1    0   1G  0 part /boot
└─sda2   8:2    0  49G  0 part /

Exam tip: MBR supports max 4 primary partitions and 2 TB disks; GPT supports up to 128 partitions and huge disks. UEFI systems require GPT.