Thank god somebody already had btrfs fuck up on them.

Horror stories awaiting ! Jesus.

A dd of a live filesystem causing trouble in the clone ? yeah I suppose tis to be expected.

sigh.

Oh god oh no what the fuck

@gogokun I was attempting to clone the system partition while it was running, btrfs apparently has some kind of journaled versioning system, so that the initial data stored on the partition didn't match up to later header versions that I am guessing are likely stored in a chained or tree fashion across the filesystem much like ext4

so what happened is the btrfs check and repair tools didn't work and the partition remained unmountable as small changes in temporary files were likely being made while the clone was occurring, however that SHOULD NOT make the drive unmountable or unfixable.

which kind of illustrates a potential problem with btrfs

look at it this way,

if i store hierarchicial metadata on files including their physical storage location, one or two files being rewritten during a clone shouldn't fuck up the WHOLE partition to the point of being irrecoverable.

its kind of concerning.

@gogokun obviously taking the drive offline and redoing it all and assigning a new uuid worked out, i also rediscovered another possible problem where a mounted clone of the efi boot part seems to prevent a new uuid assignment for the clone.

saw this before you see and of course good old bios on my machine doesn;t seem to want to let me simply turn off a hard drive, so couldn't test what i would have done with a live boot usb and the external drive on a desktop.

@gogokun yeah create two virtual disks.

one btrfs partition on each

make the first drive your boot drive

install fedora or something, which is what i use.

then run dd if=/dev/{mainbtrfs} of=/dev/{targetbtrfs} status=progress bs={block-size}

and let it run.

meanwhile for shits and giggles open a browser.

once it runs try to assign a new uuid to the target partition.

it should complain and say the tree-root is off or something like that.

@gogokun and no the os does not lock the source partition even if its mounted.