mdmon needs to keep running during the switchroot out of (at boot) and then back into (at shutdown) the initrd. It runs until a new mdmon takes over. Killmode=none is used to achieve this, with the help of --offroot which sets argv[0][0] to '@' which systemd understands. This is needed because mdmon is currently run in system-mdmon.slice which conflicts with shutdown.target so without Killmode=none mdmon would get killed early in shutdown when system.mdmon.slice is removed. As described in systemd.service(5), this conflict which shutdown can be resolved by explicitly requesting system.slice, which is a natural counterpart to DefaultDependencies=no. So add that, and also add IgnoreOnIsolate=true to avoid another possible source of an early death. With these we no longer need KillMode=none which the systemd developers have marked as "deprecated". Signed-off-by: NeilBrown <neilb@xxxxxxx> --- systemd/mdmon@.service | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/systemd/mdmon@.service b/systemd/mdmon@.service index 3502fadc3fc4..3ab908c45a3b 100644 --- a/systemd/mdmon@.service +++ b/systemd/mdmon@.service @@ -10,6 +10,9 @@ Description=MD Metadata Monitor on /dev/%I DefaultDependencies=no Before=initrd-switch-root.target Documentation=man:mdmon(8) +# allow this to keep running after switchroot, until a new +# instance is started +IgnoreOnIsolate=true [Service] # The mdmon starting in the initramfs (with dracut at least) @@ -22,4 +25,6 @@ ExecStart=BINDIR/mdmon --foreground --offroot --takeover %I # it out) and systemd will remove it when transitioning from # initramfs to rootfs. #PIDFile=/run/mdadm/%I.pid -KillMode=none +# The default slice is system-mdmon.slice which Conflicts +# with shutdown, causing mdmon to exit early. So use system.slice. +Slice=system.slice