How to check file system integrity in Linux?

To check file system integrity in Linux, you can use the fsck (File System Consistency Check) utility. This tool scans and repairs inconsistencies in the file system, ensuring data integrity and proper functioning of the storage device.

Steps to Check File System Integrity:

Unmount the File System:
Before running fsck, the file system must be unmounted. If you want to check the root file system, you need to boot into a live environment or use a rescue mode.
Example:
```
sudo umount /dev/sdX1  # Replace /dev/sdX1 with the correct partition
```
Run fsck:
Use the fsck command followed by the device name or mount point.
Example:
```
sudo fsck /dev/sdX1  # Replace /dev/sdX1 with the correct partition
```
For the root file system, you can specify it during boot by adding fsck.mode=force or fsck.repair=yes to the kernel parameters.
Automated Checks During Boot:
Most Linux distributions automatically check the file system during boot if the system was not shut down cleanly. You can also configure the system to check the file system periodically by modifying the /etc/fstab file.
Example entry in /etc/fstab:
```
/dev/sdX1  /mnt/data  ext4  defaults  0  2
```
The 2 in the last column indicates that the file system should be checked during boot.
Check File System Type:
Use the blkid or lsblk -f command to identify the file system type before running fsck.
Example:
```
sudo blkid /dev/sdX1
```
Repair File System:
If fsck finds errors, it will prompt you to repair them. Use the -y option to automatically repair without prompting:
```
sudo fsck -y /dev/sdX1
```

Example Scenario:

If you suspect corruption on a partition /dev/sda1 mounted at /home, you would:

Unmount the partition:
```
sudo umount /home
```
Run fsck:
```
sudo fsck /dev/sda1
```
Remount the partition after the check:
```
sudo mount /dev/sda1 /home
```

For systems hosted on Tencent Cloud, you can use Cloud Block Storage (CBS) for reliable and durable storage. CBS provides automated snapshot and backup features to ensure data integrity, reducing the need for manual file system checks. Additionally, Tencent Cloud File Storage (CFS) offers a managed file system service with built-in redundancy and consistency checks, ideal for distributed environments.