It looks like zvol is correctly set up in the container. However, docker runs on vfs storage driver by default and its daemon refuses to start if I try to manually change it to overlay2.
failed to start daemon: error initializing graphdriver: driver not supported: overlay2
Does anyone here have any experience with that? Should it work, and I missed something, or I just overestimated the capabilities of zvols?
Which distribution do you use as host OS ? On my side, I use Ubuntu 22.04.
On other thing I configure on LXD side is shiftfs, I disable it explicitly, I had many issues in the past with it regarding storage. Now, idmapped mounts (the official implementation of it in the kernel) is working fine with ext4 (even inside a zvol)
$ lxc info | grep shiftfs
shiftfs: "false"
$ lxc info | grep idmapped
idmapped_mounts: "true"
idmapped_mounts_v2: "true"
$ uname -a
Linux hypervisor 5.15.0-73-generic #80-Ubuntu SMP Mon May 15 15:18:26 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux
But that would mean that the answer to my question would be negative on a standard Ubuntu 22.04 installation, which would be pretty important, as I guess thatâs the main use case for zvols in LXD/LXC. I wonder if thatâs the case.
Wow, thatâs significant info that should be mentioned somewhere in the docs next to the zvol documentation, as it impacts the latest Ubuntu LTS version and the main use case for zvols. I guess Iâll be upgrading the kernel and weâll see.