Ext2 File System Programs

This guide will go over the numerous tools this software suite has to offer, basic and advanced filesystem and recovery options.

Information

e2fsprogs is one of the preinstalled packages for our r/Techsupport Rescue Media. If you are using this live image, you can skip the installation section.

How to install e2fsprogs

Refer below for installation instructions if you are not using our live image or want to install it on your own system.

Installing e2fsprogs

Debian / Ubuntu / Linux Mint:

sudo apt update && sudo apt install e2fsprogs

Fedora / RHEL / CentOS / AlmaLinux:

sudo dnf install e2fsprogs

Arch / Manjaro / CachyOS:

sudo pacman -Syu e2fsprogs

Tools

The rest of the guide will be going over the different methods and tools available. Note, it is best to have a basic understanding of what stuff like /dev/sdb and /dev/sdb1 represent. A guide to understanding it can be found here.

Warning

Some of these operations are DESTRUCTIVE (i.e. they will delete data). Double check the comments before running the commands.

Basic Repair Operations

Check and Repair Filesystem (e2fsck)

Basic automatic repair:

# Unmount first (REQUIRED)
sudo umount /dev/sdb1

# Automatic repair (answer yes to all)
sudo e2fsck -y /dev/sdb1

# Force check even if filesystem appears clean
sudo e2fsck -fy /dev/sdb1

Interactive repair:

# Manual decisions for each error
sudo e2fsck /dev/sdb1

# With verbose output
sudo e2fsck -v /dev/sdb1

Check for bad blocks during repair:

# Read-only bad block scan + filesystem check
sudo e2fsck -c /dev/sdb1

# Read-write bad block scan (DESTRUCTIVE - erases data)
sudo e2fsck -cc /dev/sdb1

Surface Scan for Bad Blocks (badblocks)

Read-only test (safe):

# Non-destructive scan, show progress
sudo badblocks -sv /dev/sdb

# Save bad block list to file
sudo badblocks -sv -o badblocks.txt /dev/sdb

# Use bad block list during filesystem check
sudo e2fsck -l badblocks.txt /dev/sdb1

Write test (DESTRUCTIVE):

# WARNING: Erases ALL data on device
sudo badblocks -wsv /dev/sdb

# Non-destructive read-write test (very slow)
sudo badblocks -nsv /dev/sdb

Resize Filesystem (resize2fs)

Expand filesystem:

# After expanding partition with gparted
# Unmount first
sudo umount /dev/sdb1

# Check filesystem before resizing
sudo e2fsck -f /dev/sdb1

# Expand to fill partition
sudo resize2fs /dev/sdb1

# Remount
sudo mount /dev/sdb1 /mnt

Shrink filesystem:

# Unmount and check
sudo umount /dev/sdb1
sudo e2fsck -f /dev/sdb1

# Shrink to specific size (e.g., 50GB)
sudo resize2fs /dev/sdb1 50G

# Now shrink partition with gparted to match

Advanced Operations

Recover Deleted Files (debugfs)

Interactive recovery:

# Open filesystem in debugfs
sudo debugfs /dev/sdb1

# Inside debugfs:
debugfs> lsdel              # List recently deleted files
debugfs> ls -d <inode>      # Check if file recoverable
debugfs> dump <inode> /tmp/recovered_file   # Recover file
debugfs> quit

Modify Filesystem Parameters (tune2fs)

View current settings:

# Display all filesystem parameters
sudo tune2fs -l /dev/sdb1 | less

Optimize for USB drives:

# Disable journaling (faster for flash drives)
sudo tune2fs -O ^has_journal /dev/sdb1

# Reduce reserved space from 5% to 1%
sudo tune2fs -m 1 /dev/sdb1

Enable/disable features:

# Enable journaling
sudo tune2fs -j /dev/sdb1

# Change to writeback mode (faster, less safe)
sudo tune2fs -o journal_data_writeback /dev/sdb1

# Set filesystem label
sudo tune2fs -L "MyDrive" /dev/sdb1

# Set max mount count before forced check
sudo tune2fs -c 30 /dev/sdb1

# Disable automatic time-based checks
sudo tune2fs -i 0 /dev/sdb1

Backup and Restore Metadata (e2image)

Create metadata backup:

# Backup filesystem metadata (not file contents)
sudo e2image -r /dev/sdb1 - | gzip > sdb1_metadata.img.gz

# Raw backup including file contents (use for recovery)
sudo e2image -ra /dev/sdb1 sdb1_backup.img

Restore metadata:

# Restore metadata from backup
zcat sdb1_metadata.img.gz | sudo e2image -I /dev/sdb1 -

Change File Attributes (chattr/lsattr)

Make files immutable:

# Prevent deletion/modification (even by root)
sudo chattr +i important_file.txt

# View attributes
lsattr important_file.txt

# Remove immutable flag
sudo chattr -i important_file.txt

Append-only files:

# Only allow appending (good for logs)
sudo chattr +a logfile.txt