Public bug reported: If /var/lib is a dataset not under <pool>/ROOT/<root_dataset>, as proposed in the ubuntu root on zfs upstream guide (https://github.com/zfsonlinux/zfs/wiki/Ubuntu-18.04-Root-on-ZFS), we end up with a race where some services, like systemd-random-seed are writing under /var/lib, while zfs-mount is called. zfs mount will then potentially fail because of /var/lib isn't empty, and so, can't be mounted. Order those 2 units for now (more may be needed) as we can't declare virtually a provide mount point to match "RequiresMountsFor=/var/lib/systemd/random-seed" from systemd-random-seed.service. The optional generator for zfs 0.8 fixes it, but it's not enabled by default nor necessarily required. Example: - rpool/ROOT/ubuntu (mountpoint = /) - rpool/var/ (mountpoint = /var) - rpool/var/lib (mountpoint = /var/lib)
Both zfs-mount.service and systemd-random-seed.service are starting After=systemd-remount-fs.service. zfs-mount.service should be done before local-fs.target while systemd-random-seed.service should finish before sysinit.target (which is a later target). Ideally, we would have a way for zfs mount -a unit to declare all paths or move systemd-random-seed after local-fs.target. ** Affects: zfs-linux (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to zfs-linux in Ubuntu. https://bugs.launchpad.net/bugs/1845298 Title: Potential race with systemd if /var/lib is an independent persistent unit Status in zfs-linux package in Ubuntu: New Bug description: If /var/lib is a dataset not under <pool>/ROOT/<root_dataset>, as proposed in the ubuntu root on zfs upstream guide (https://github.com/zfsonlinux/zfs/wiki/Ubuntu-18.04-Root-on-ZFS), we end up with a race where some services, like systemd-random-seed are writing under /var/lib, while zfs-mount is called. zfs mount will then potentially fail because of /var/lib isn't empty, and so, can't be mounted. Order those 2 units for now (more may be needed) as we can't declare virtually a provide mount point to match "RequiresMountsFor=/var/lib/systemd/random-seed" from systemd-random-seed.service. The optional generator for zfs 0.8 fixes it, but it's not enabled by default nor necessarily required. Example: - rpool/ROOT/ubuntu (mountpoint = /) - rpool/var/ (mountpoint = /var) - rpool/var/lib (mountpoint = /var/lib) Both zfs-mount.service and systemd-random-seed.service are starting After=systemd-remount-fs.service. zfs-mount.service should be done before local-fs.target while systemd-random-seed.service should finish before sysinit.target (which is a later target). Ideally, we would have a way for zfs mount -a unit to declare all paths or move systemd-random-seed after local-fs.target. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/zfs-linux/+bug/1845298/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp