btrfs COW breaks Virtualbox

btrfs copy on write breaks VirtualBox so that starting a VM will often not complete due to spurious disk errors.

I'm trying out the chattr fix that turns off COW.

I've just done this:

cd ~/VirtualBox\ VMs

for f in `find . -name '*.vdi'`

do

  F=$f

  T=tmpfile

  touch $T

  chattr =C $T

  dd if=$F of=$T bs=1M

  rm $F

  mv $T $F

done

Here's hoping it all works :-).  It's faster than mkfs.ext4 and restore from backup :-).