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What scenarios causes a hard drive UUID to change? Are there any manufacturer assigned unique ids for hard drives that is less likely to change?

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up vote 5 down vote accepted

The Universally Unique Identifier (UUID) is integrated in the filesystem. By this we can recognize a filesystem by it's unique number to avoid confusion (e.g. when mounting drives).

Anything that affects the file-system will also change its UUID. Under normal circumstances this will be

  • formatting a drive
  • (re-)partitioning of a drive

Under rare circumstances we may be faced with an external drive that mounts a temporary filesystem (e.g. live systems booting from an USB drive). In this case the UUID may also change.

We can manually assign a fixed UUID to a drive if we wish:

This would be another scenario where the UUID of a drive changes.

In case we need manual control over the disk identifiers we may also use a disk LABEL:

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