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Any ideas on what causes the docker issue? Or have you not poked it with a stick yet?

• LukeShu 3y ago
  I haven't had a chance to dig in to it yet. Most of the time, Docker uses `overlayfs` to emulate COW, but on btrfs it can just use the filesystem's native COW. In my mind it's about equally likely that it's Docker's fault as it is btrfs's fault; that perhaps Docker's btrfs storage driver is doing something dumb. https://docs.docker.com/storage/storagedriver/select-storage-driver/ https://docs.docker.com/storage/storagedriver/select-storage...
  • pxc 3y ago
    For VMs and containers isn't it pretty common to use a subvol where CoW is disabled for their disk images? Same thing for ZFS with datasets that disabled CoW for things like that.
    • curt15 3y ago
      > Same thing for ZFS with datasets that disabled CoW for things like that. Does ZFS let you disable CoW?
      • pxc 3y ago
        Huh. Looks like it doesn't! I knew that BTRFS did and saw that it was on the roadmap for bcachefs, and assumed it was something you could tweak in ZFS as well.