After some experimentation I've found that with no 'linux-image-extra- virtual' package installed (whether it's installed or not makes no difference) and all other package versions at the same level the command does work when the backing store is specified as 'overlayfs' instead of 'overlay'.
root@lxchost-xenial3:~# lxc-copy --name=cache --newname overlayfs1 -B overlayfs --snapshot root@lxchost-xenial3:~# grep rootfs /var/lib/lxc/overlayfs1/config lxc.rootfs = overlayfs:/var/lib/lxc/cache/rootfs:/var/lib/lxc/overlayfs1/delta0 lxc.rootfs.backend = overlayfs root@lxchost-xenial3:~# grep overlay /proc/filesystems nodev overlayfs nodev overlay root@lxchost-xenial3:~# lxc-copy --name=cache --newname overlayfs2 -B overlay --snapshot lxc-copy: bdev/bdev.c: bdev_copy: 381 no such block device type: overlay lxc-copy: lxccontainer.c: copy_storage: 2844 Error copying storage. clone failed So it would appear that the backing store is supported, but the man page and the tooling do not match in functionality. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to lxc in Ubuntu. https://bugs.launchpad.net/bugs/1591513 Title: lxc-copy: bdev/bdev.c: bdev_copy: 381 no such block device type: overlay Status in lxc package in Ubuntu: New Bug description: Description: Ubuntu 16.04 LTS Release: 16.04 lxc: Installed: 2.0.1-0ubuntu1~16.04.1 linux-image-virtual: Installed: 4.4.0.24.25 linux-image-extra-virtual: Installed: 4.4.0.24.25 Man ref: http://manpages.ubuntu.com/manpages/xenial/man1/lxc-copy.1.html Problem: The man package references 'overlay' as a backing storage type, but when the following command is executed: lxc-copy --name=cache --newname overlayfs1 -B overlay --snapshot The result is: lxc-copy: bdev/bdev.c: bdev_copy: 381 no such block device type: overlay lxc-copy: lxccontainer.c: copy_storage: 2844 Error copying storage. clone failed Expected result: An overlay snapshot should be created. Existing workaround: Use the deprecated lxc-clone command instead: lxc-clone --snapshot --backingstore overlayfs --orig cache --new overlayfs1 Steps to recreate: apt-get update && apt-get install -y lxc lxc-create --name=cache --template=download -- --dist ubuntu --release trusty --arch amd64 lxc-copy --name=cache --newname overlayfs1 -B overlay --snapshot To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1591513/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
