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Hands-on Lab·Linux Foundation Certified System Administrator

Mounting filesystems and making them survive reboot

A filesystem that is not mounted does nothing, and an fstab line that is wrong can stop a machine booting. This guide mounts a filesystem three different ways, writes the fstab entry properly, verifies it before trusting it, and shows what to do when an unmount is refused.

Storage Guide 32 of 38 Beginner

util-linux on both families - mount, umount, findmnt and blkid are identical. systemd generates a .mount unit from every fstab line, which is why systemctl daemon-reload belongs in this workflow on both.

Captured on the Ubuntu host. Every block device on this page is a loop device made from a file, created and destroyed inside the transcript - no disk on the host was touched.
Server NameIP AddressOSRolesCPURAMHDD
LFCS-A01192.168.0.70Ubuntu 26.04 LTSPrimary host - most guides run only here2 Core4 GB50 GB

This guide includes

Use this because a filesystem that is not mounted does nothing, and a wrong fstab line stops the boot. This matters because that line can be verified before you ever trust a reboot to it.

Before you start

  1. A filesystem, and the names it answers to

  2. Mounting it, and what a mount point is

  3. Three ways to say the same device

  4. The fstab line, and checking it before you trust it

  5. Applying it without a reboot

  6. Options that change what the filesystem allows

  7. When an unmount is refused

  8. Putting the host back

Official sources

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