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When cloning a drive (using dd), will the UUID's for each partition change, or are they hardware specific? or does cloning it preserve the UUID as well?

What happen if a system detected two devices with the same UUID?

Matt Clark
  • 2,104

1 Answers1

13

UUIDs are not hardware-specific but stored in the partition's filesystem. That means cloning a disk or partition with dd will result in the same UUID.

You can assign a new UUID by using:

  • tune2fs -U random <device> (ext2/ext3/ext4)
  • xfs_admin -U generate <device> (xfs)
  • reiserfstune -u $(uuidgen) <device> (reiserfs)
  • mkswap -U $(uuidgen) <device> (swap)

Having duplicated UUIDs doesn't necessarily lead to errors. However booting and mounting a device by UUID will become ambiguous and may lead to the wrong device being used.

scai
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