1: Search a disk for bad blocks by using a non-destructive read-only test

Code:

sudo badblocks /dev/sdX

Motivation: This use case is useful when you want to check a disk for any bad blocks without making any changes to the data. It performs a non-destructive read-only test, allowing you to identify any potential issues without risking data loss.

Explanation:

• sudo: Executes the command with administrative privileges.
• badblocks: The command used for searching bad blocks on a device.
• /dev/sdX: The path of the disk you want to inspect. Replace sdX with the actual disk identifier (e.g., sda, sdb, etc.).

Example Output:

Checking blocks 0 to 1953458175
Checking for bad blocks (read-only test): done
Pass completed, 0 bad blocks found. (0/0/0 errors)

2: Search an unmounted disk for bad blocks with a non-destructive read-write test

Code:

sudo badblocks -n /dev/sdX

Motivation: Use this command when you want to perform a more comprehensive test on an unmounted disk. The non-destructive read-write test verifies the integrity of the disk by writing and checking data, allowing you to identify potential issues and fix them without erasing any existing data.

Explanation:

• -n: Specifies a non-destructive read-write test.
• /dev/sdX: The path of the disk you want to inspect. Replace sdX with the actual disk identifier.

Example Output:

Checking blocks 0 to 1953458175
Checking for bad blocks (non-destructive read-write test): done
Pass completed, 0 bad blocks found. (0/0/0 errors)

3: Search an unmounted disk for bad blocks with a destructive write test

Code:

sudo badblocks -w /dev/sdX

Motivation: This command is useful when you suspect that a disk has bad blocks and you want to perform a more aggressive test. The destructive write test overwrites the entire disk, identifying and marking any bad blocks it encounters along the way.

Explanation:

• -w: Initiates a destructive write test.
• /dev/sdX: The path of the disk you want to inspect. Replace sdX with the actual disk identifier.

Example Output:

Checking for bad blocks (destructive read-write test): done
Pass completed, 0 bad blocks found. (0/0/0 errors)

4: Search an unmounted disk for bad blocks with a destructive write test and show verbose status

Code:

sudo badblocks -svw /dev/sdX

Motivation: When performing a destructive write test, it can be helpful to have a detailed progress report. This command provides verbose status information, allowing you to monitor the test’s progress and quickly identify any issues.

Explanation:

• -s: Enables the show progress flag.
• -v: Enables verbose output mode.
• -w: Initiates a destructive write test.
• /dev/sdX: The path of the disk you want to inspect. Replace sdX with the actual disk identifier.

Example Output:

Checking for bad blocks (destructive read-write test): 16.37% done, 0:01 elapsed. (0/0/0 errors)

5: Search an unmounted disk in destructive mode and output found blocks to a file

Code:

sudo badblocks -o path/to/file -w /dev/sdX

Motivation: When performing a destructive write test, it can be useful to save the list of bad blocks for further analysis or to use it for making informed decisions about the disk’s future use. This command allows you to specify a file path where the list of bad blocks will be saved.

Explanation:

• -o path/to/file: Specifies the output file path. Replace path/to/file with the desired location and file name.
• -w: Initiates a destructive write test.
• /dev/sdX: The path of the disk you want to inspect. Replace sdX with the actual disk identifier.

Example Output: If the test finds any bad blocks, their locations will be saved in the specified file.

6: Search an unmounted disk in destructive mode with improved speed using 4K block size and 64K block count

Code:

sudo badblocks -w -b 4096 -c 65536 /dev/sdX

Motivation: By default, badblocks uses a 1K block size and a 64 block count, which can be time-consuming for large disks. This command allows you to adjust the block size and count, which can significantly improve the test speed when dealing with high-capacity disks.

Explanation:

• -w: Initiates a destructive write test.
• -b 4096: Sets the block size to 4096 bytes (4K). Modify the value as needed.
• -c 65536: Specifies the block count. In this example, it is set to 65536. Adjust the value according to your requirements.
• /dev/sdX: The path of the disk you want to inspect. Replace sdX with the actual disk identifier.

Example Output:

Checking for bad blocks (destructive read-write test): done
Pass completed, 0 bad blocks found. (0/0/0 errors)

Conclusion

In this article, we explored different use cases of the badblocks command. Whether you need to perform a read-only test, a non-destructive read-write test, or a more aggressive destructive write test, badblocks provides the necessary functionality to identify and manage bad blocks on your disks. By understanding the different options and arguments available, you can customize the command to suit your specific needs and ensure the integrity of your storage devices.