How to Use shred to Erase a Drive or File in Fedora

Chinese Version: https://blog.csdn.net/sch0120/article/details/140390291

How to Use shred to Erase a Drive or File in Fedora

Erasing a drive securely is crucial to protect your sensitive data from unauthorized access. In this blog post, we will learn how to use the shred command in Fedora to securely erase a whole drive or a specific partition. shred overwrites the specified files repeatedly to make it harder for even sophisticated recovery techniques to retrieve the data.

Installing shred

The shred command is part of the GNU coreutils package, which is usually pre-installed on Fedora. To verify if it’s installed, you can run:

shred --version

If shred is not installed, you can install it using:

sudo dnf install coreutils

Understanding the shred Command

The shred command has several useful options that allow you to customize the erasure process. Here are some of the most commonly used options:

• -n or --iterations: Specifies the number of times to overwrite the file. More iterations make it harder to recover the data. The default is 3.
• -v or --verbose: Displays the progress of the overwriting process.
• -z or --zero: Adds a final overwrite with zeros to hide the shredding process.
• -u or --remove: After shredding, remove the file. (this option is not for operating on device files)

Steps to Erase a Whole Disk

Warning: This process will completely erase all data on the specified disk. Ensure you have backups of any important data.

1. Identify the disk to be erased. Use the lsblk or fdisk command to list all the disks and partitions.

   lsblk -p
   

2. Use shred to erase the entire disk. Replace /dev/sdX with your actual disk identifier.

   sudo shred -v -n 3 -z /dev/sdX
   

   This command will:

   • Overwrite the entire disk 3 times with random data (-n 3).
   • Display the progress (-v).
   • Add a final overwrite with zeros to hide the shredding process (-z).

Steps to Erase a Specific Partition

1. Identify the partition to be erased. Use the lsblk or fdisk command to list all the disks and partitions.

   lsblk -p
   

2. Use shred to erase the specific partition. Replace /dev/sdXn with your actual partition identifier.

   sudo shred -v -n 3 -z /dev/sdXn
   

   This command will:

   • Overwrite the partition 3 times with random data (-n 3).
   • Display the progress (-v).
   • Add a final overwrite with zeros to hide the shredding process (-z).

Shredding a File

In addition to erasing drives and partitions, shred can also be used to securely delete files. Here’s a brief example:

shred -v -u -n 3 -z filename

This command will:

• Overwrite the file 3 times with random data (-n 3).
• Display the progress (-v).
• Add a final overwrite with zeros (-z).
• Remove the file after shredding (-u).

Conclusion

Using shred is an effective way to securely erase data on a drive, partition, or individual file in Fedora. The options provided by shred allow you to customize the overwriting process to meet your security needs. Remember, erasing data is irreversible, so always ensure you have backups of any important information before proceeding.

By following the steps outlined in this guide, you can confidently use shred to protect your sensitive data from unauthorized recovery.