What is stored in the /sbin directory?
/sbin holds the system-administration binaries — tools meant for root, like fdisk, mkfs, fsck, shutdown, and ip.
The split from /bin is about audience, not mechanism. /bin has commands everyone uses; /sbin has commands that change the system itself, which normally only the administrator should run:
| Command | Job |
|---|---|
fdisk, mkfs |
Partition disks, create filesystems |
fsck |
Check and repair a filesystem |
ip (older: ifconfig) |
Configure networking |
shutdown, reboot |
Control system power state |
These aren't locked away — a regular user can often run them — but most refuse to do anything useful without root privileges, because formatting a disk or reconfiguring the network is exactly what you don't want an unprivileged user doing by accident. Putting them in a separate directory also keeps them out of normal users' tab-completion noise.
Modern Linux: like /bin, /sbin is now usually a symlink to /usr/sbin after the usr-merge, so the physical separation is historical even though the conceptual one (admin vs. everyday tools) still holds.
Mnemonic: sbin = system (or superuser) binaries.