Maintaining the Integrity of Filesystems: A Comprehensive Guide for LPIC-1 #
Maintaining the integrity of filesystems is crucial for ensuring the reliability and performance of your Linux systems. This guide covers essential commands and utilities for verifying filesystem integrity, monitoring space, and repairing filesystem issues on both Ubuntu/Debian and Enterprise Linux distributions.
Key Knowledge Areas #
- Verify the integrity of filesystems.
- Monitor free space and inodes.
- Repair simple filesystem problems.
Important Commands and Utilities #
du
df
fsck
e2fsck
mke2fs
tune2fs
xfs_repair
xfs_fsr
xfs_db
Verify the Integrity of Filesystems #
Ubuntu/Debian #
fsck (File System Consistency Check)
The fsck
command is used to check and optionally repair one or more Linux filesystems.
sudo fsck /dev/sdXn
-A
: Check all filesystems.-R
: Skip root filesystem.-N
: Don’t execute, just show what would be done.
e2fsck
Specifically for ext2/ext3/ext4 filesystems.
sudo e2fsck -f /dev/sdXn
Enterprise Linux (RHEL/CentOS) #
fsck
sudo fsck /dev/sdXn
xfs_repair
Used for XFS filesystems, which are common in Enterprise Linux environments.
sudo xfs_repair /dev/sdXn
Monitor Free Space and Inodes #
Ubuntu/Debian #
df (Disk Free)
Displays the amount of disk space available on the filesystem.
df -h
-h
: Human-readable format.
du (Disk Usage)
Estimates file space usage.
du -sh /path/to/directory
-s
: Display only a total for each argument.-h
: Human-readable format.
Enterprise Linux (RHEL/CentOS) #
df
df -h
du
du -sh /path/to/directory
Repair Simple Filesystem Problems #
Ubuntu/Debian #
fsck
Run fsck
with the -y
option to automatically answer ‘yes’ to prompts.
sudo fsck -y /dev/sdXn
e2fsck
Force checking and repair.
sudo e2fsck -p /dev/sdXn
Enterprise Linux (RHEL/CentOS) #
fsck
sudo fsck -y /dev/sdXn
xfs_repair
sudo xfs_repair /dev/sdXn
Additional Commands and Utilities #
Ubuntu/Debian #
mke2fs
Used to create an ext2/ext3/ext4 filesystem.
sudo mke2fs /dev/sdXn
tune2fs
Adjusts tunable filesystem parameters on ext2/ext3/ext4 filesystems.
sudo tune2fs -l /dev/sdXn
Enterprise Linux (RHEL/CentOS) #
xfs_fsr
Reorganizes and defragments XFS filesystems.
sudo xfs_fsr /dev/sdXn
xfs_db
Debugs an XFS filesystem.
sudo xfs_db /dev/sdXn
Real-World Examples #
Example 1: Checking and Repairing an ext4 Filesystem #
Unmount the filesystem:
sudo umount /dev/sdXn
Run
e2fsck
to check and repair:sudo e2fsck -f /dev/sdXn
Example 2: Checking and Repairing an XFS Filesystem #
Unmount the filesystem:
sudo umount /dev/sdXn
Run
xfs_repair
:sudo xfs_repair /dev/sdXn
Example 3: Monitoring Disk Usage #
Check disk space usage:
df -h
Check directory space usage:
du -sh /var/log
By mastering these commands and understanding the differences between Ubuntu/Debian and Enterprise Linux, you’ll be well-prepared to maintain filesystem integrity and handle related issues effectively.