I recently have some issue with docker and btrfs which makes me want to
learn more about it. The reason I have used
btrfs is to solve some
issues with device mapper.
I use docker with
btrfs. Recently, for some reasons the
/var/lib/docker grow to 100% disk space and docker unable to start
with some error about opening db file or so.
I tried to take a snapshot of EBS volume and resize it with
as I always do when resizing volume on EBS. But turning out that doesn’t
work due to
Luckily I found an much nicer way to increase. Simply add a new volume, then using this:
sudo btrfs device add -f /dev/xvdc /var/lib/docker
This adds extra space to
/var/lib/docker. At least, this will make
docker start backup and I can backup my docker image or inspect/debug
some existing container.