Mdadm does not wait enough time when mdmon is started by systemd. It causes various problems with behaviour of a RAID volume with external metadata. For example: mdmon does not update a value of checkpoint during migration and second RAID5 volume is read-only after reboot done during container reshape (both problems occur with IMSM matadata). If a type of process start-up is changed to 'forking', systemctl will wait until mdmon (parent) process exits after calling fork. This way mdmon will always be fully initialized after start_mdmon and these problems will not occur. In this case it is recommended to add a path to PIDFile, so that systemd does not have to guess a PID of the mdmon process. Signed-off-by: Pawel Baldysiak <pawel.baldysiak@xxxxxxxxx> Reviewed-by: Artur Paszkiewicz <artur.paszkiewicz@xxxxxxxxx> Reviewed-by: Lukasz Dorau <lukasz.dorau@xxxxxxxxx> --- systemd/mdmon@.service | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/systemd/mdmon@.service b/systemd/mdmon@.service index 5520cd0..304b26e 100644 --- a/systemd/mdmon@.service +++ b/systemd/mdmon@.service @@ -14,5 +14,7 @@ Before=initrd-switch-root.target # mdmon should never complain due to lack of a platform, # that is mdadm's job if at all. Environment=IMSM_NO_PLATFORM=1 -ExecStart=/sbin/mdmon --foreground %I +ExecStart=/sbin/mdmon %I +Type=forking +PIDFile=/run/mdadm/%I.pid KillMode=none -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
