Linux Filesystems and Mounts Cheat Sheet

sudo mount /dev/sdb1 /mnt/data

# Mount a block device using filesystem auto-detection.

sudo mount -o ro /dev/sdb1 /mnt/data

# Useful for safe inspection or recovery work.

sudo mount UUID=1234-ABCD /mnt/data

# Use a stable identifier instead of a device name.

sudo mount --bind /srv/data /mnt/data

# Expose the same directory tree at another path.

sudo mount -o remount,rw /mnt/data

# Change mount options for a mounted filesystem.

sudo umount /mnt/data

# Detach a mounted filesystem.

sudo umount -l /mnt/data

# Detach the mount now and clean up after current users release it.

sudo fuser -vm /mnt/data

# Helpful before an unmount that fails with target is busy.

sudo lsof +f -- /mnt/data

# Find which processes still hold files on a mounted filesystem.

findmnt -T /mnt/data

# Show which filesystem backs a path and how it is mounted.

sudo mount -o loop image.iso /mnt/iso

# Loop-mount a disk image file.

sudo losetup -fP disk.img

# Map a disk image file to the next free loop device.

losetup -a

# Show loop device mappings.

sudo losetup -d /dev/loop0

# Disconnect a loop device from its image file.

sudoedit /etc/fstab

# Configure persistent mounts, swap, and mount options.

lsblk -f

# Collect UUIDs and labels for robust /etc/fstab entries.

sudo mount -a

# Validate /etc/fstab without rebooting.

sudo systemctl daemon-reload

# Useful when fstab is consumed into mount units.

systemctl list-units --type=mount

# See active mount units managed by systemd.

findmnt --fstab

# Render how the system interprets /etc/fstab.

sudo systemd-analyze verify /etc/fstab

# Catch syntax and boot-time mounting issues early.

systemctl status mnt-data.mount

# Inspect mount unit logs and status from systemd.

journalctl -b | grep -i mount

# Review boot logs when a filesystem did not mount.

systemd-escape -p --suffix=mount /mnt/data

# Convert a path into the corresponding systemd mount unit name.

sudo fsck /dev/sdb1

# Dispatch to the correct fsck helper based on filesystem type.

sudo e2fsck -f /dev/sdb1

# Run a full ext filesystem check even if marked clean.

sudo e2fsck -y /dev/sdb1

# Automatically answer yes to filesystem repairs.

sudo xfs_repair /dev/sdb1

# XFS consistency repair tool.

sudo badblocks -sv /dev/sdb

# Perform a read-only bad-block scan.

sudo badblocks -wsv /dev/sdb

# Use only on disks you can erase completely.

sudo smartctl -H /dev/sda

# Quick disk health check for SMART-capable devices.

sudo smartctl -a /dev/sda

# Inspect temperatures, reallocated sectors, and error logs.

sudo smartctl -t short /dev/sda

# Schedule a quick device self-test.

sudo smartctl -l selftest /dev/sda

# Review completed SMART test results.

sudo nvme list

# Inventory NVMe namespaces and firmware details.

sudo nvme smart-log /dev/nvme0

# Inspect NVMe wear, temperature, and media error counters.