Any chance to recovery btrfs raid-0 after accidental format of one volume?
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Bad case of user error here but I managed to reformat one half of a btrfs volume that was set up with metadata raid-1 and data raid-0.
It won't help you - but did you format it with mkfs.btrfs, while it was mounted?
mkfs.btrfs behaves very dangerously here.
For example, we have a block device in use:
# cat /proc/swaps Filename Type Size Used Priority /dev/md0 partition 10233276 0 -1
mkfs for other filesystems will refuse to touch it, because it's in use:
# mkfs.ext4 /dev/md0 mke2fs 1.41.14 (22-Dec-2010) /dev/md0 is mounted; will not make a filesystem here!
# mkfs.xfs /dev/md0 mkfs.xfs: cannot open /dev/md0: Device or resource busy
mkfs.btrfs doesn't see a problem in creating a filesystem on a mounted block device:
# mkfs.btrfs /dev/md0
WARNING! - Btrfs Btrfs v0.19 IS EXPERIMENTAL WARNING! - see http://btrfs.wiki.kernel.org before using
fs created label (null) on /dev/md0
nodesize 4096 leafsize 4096 sectorsize 4096 size 9.76GB
Btrfs Btrfs v0.19
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Tomasz Chmielewski http://wpkg.org