Change Partition Serial Number? How To Do It
Yes, you can change a partition’s serial number, but the method depends on the operating system and the filesystem. On Windows, you can use the built-in vol command to view it and label to change the volume label, but the serial number itself is not directly changeable with built-in tools; you need third-party software. On Linux, you can use tune2fs for ext filesystems or mlabel for FAT/exFAT. This article explains what a partition serial number is, why you might want to change it, and the safe ways to do it.
What Is a Partition Serial Number?
A partition serial number is a unique identifier assigned to a filesystem when it is created. It is stored in the filesystem’s metadata, not in the partition table (MBR or GPT). For example, NTFS volumes have a 32-bit hex serial number, while ext4 has a 128-bit UUID. This number is used by the operating system to track volumes, and it appears in tools like blkid on Linux or vol on Windows. It is different from the partition’s GUID in GPT, which identifies the partition itself, not the filesystem.
Why Change a Partition Serial Number?
There are a few legitimate reasons to change a partition serial number:
- Cloning conflicts: If you clone a disk, the clone gets the same serial number as the original. This can cause confusion when both disks are connected, as some software may not distinguish them.
- Software licensing: Some software ties its license to the volume serial number. If you replace a hard drive and restore from an image, the new volume may have a different serial number, triggering a re-activation. Changing it back can help.
- Forensics or testing: In a lab, you might want to simulate a specific serial number for testing purposes.
- Privacy: The serial number can be used to track a device, so some privacy-conscious users change it.
Note that changing a serial number does not affect the data on the partition, but it can break things that rely on the original number, such as boot entries or activation.
How to View the Current Serial Number
Before changing, you should know the current value. Here is how to view it on different systems:
- Windows: Open Command Prompt and type
vol C:(replace C: with your drive letter). It shows the volume serial number in hex. - Linux: Use
blkid(requires root) to see the UUID of all filesystems. For ext filesystems,tune2fs -l /dev/sda1shows the UUID. - macOS: Use
diskutil info /dev/disk1s1to see the volume UUID.
How to Change the Serial Number
The method depends on the filesystem. Here are the common ones:
Windows (NTFS)
Windows does not provide a built-in command to change the NTFS serial number. You need a third-party tool like VolumeID from Sysinternals (now Microsoft) or a hex editor. VolumeID is a command-line tool that can set a new serial number. For example:
volumeid C: 1234-5678This changes the serial number of the C: drive to 1234-5678. The tool works on NTFS and FAT volumes. Always back up your data before using such tools, and ensure the volume is not in use.
Linux (ext4, ext3, ext2)
For ext filesystems, use tune2fs:
sudo tune2fs -U random /dev/sda1This sets a random UUID. You can also specify a specific UUID, e.g., -U 12345678-1234-1234-1234-123456789abc. For FAT/exFAT, use mlabel from the mtools package:
mlabel -i /dev/sdb1 ::1234-5678Note that FAT serial numbers are 32-bit, often displayed as two 16-bit groups.
macOS (APFS, HFS+)
macOS does not offer a built-in way to change the volume UUID. You would need to reformat the volume or use third-party tools. Reformatting erases data, so it is not recommended unless you have a backup.
Common Problems and Misconceptions
One common misconception is that changing the serial number will speed up the disk or fix errors. It will not. The serial number is purely an identifier. Another issue is that some tools may not work on system volumes because the OS locks them. You may need to boot from a recovery environment or use a live Linux USB to change the serial number of the system partition.
Another problem: if you change the serial number of a boot drive, the boot configuration (BCD) may reference the old serial number, causing a boot failure. On Windows, you may need to run bootrec /rebuildbcd from the recovery console. On Linux, you may need to update /etc/fstab if it uses UUIDs.
Risks and Safety Considerations
Changing a partition serial number is generally safe if done correctly, but there are risks:
- Data corruption: If the tool crashes mid-write, the filesystem could be corrupted. Always back up important data.
- Boot failure: As mentioned, boot loaders may rely on the serial number. Have a recovery plan.
- Software activation: Some software may deactivate if it detects a change. You might need to re-enter license keys.
Always use reputable tools and follow the instructions precisely. For critical systems, test in a virtual machine first.
Alternatives to Changing the Serial Number
If your goal is to avoid conflicts from cloned disks, you can often just change the drive letter or mount point instead. On Windows, you can assign a different drive letter in Disk Management. On Linux, you can change the mount point in /etc/fstab. For licensing issues, you might contact the software vendor for a reset rather than changing the serial number. If you need a unique ID for backup or sync purposes, consider using a file-based identifier instead.
Frequently Asked Questions
Is it legal to change a partition serial number?
Yes, it is legal in most jurisdictions. The serial number is not a security feature; it is an identifier. However, using it to bypass software licensing may violate the software’s terms of service.
Can I change the serial number of a USB flash drive?
Yes, if the USB drive uses FAT32 or NTFS, you can use the same tools as for internal drives. For exFAT, you can use mlabel on Linux. Some USB drives have a fixed serial number in the controller, which you cannot change.
Will changing the serial number delete my files?
No, changing the serial number only modifies the filesystem metadata, not the data. However, if the tool is interrupted, it could cause corruption, so back up first.
How do I find the serial number of a partition on Windows without a command line?
You can use Disk Management, but it does not show the serial number. You can use the vol command in Command Prompt, or use third-party tools like CrystalDiskInfo. Some properties dialogs show it, but not always.
Does changing the serial number affect the partition table?
No, the partition table (MBR or GPT) contains partition entries, not filesystem serial numbers. The serial number is inside the filesystem boot sector or superblock.
Can I set a custom serial number on an exFAT drive?
Yes, you can use mlabel on Linux to set a custom serial number on exFAT. On Windows, you can use a hex editor to modify the boot sector, but it is riskier.
Related
Method: the standard formula for this calculation, rounded as each result states. See how the calculators work or report an error.