Normally "mdadm -I" will not start an array if it has reason to
expect further devices.
This means that if a device is removed while the host is shut down,
"mdadm -I" will never start the device.
If the array is know to the host, it make sense to start the array
anyway after a reasonable timeout.
This patch adds systemd/udev infrastructure so that 30 seconds after
a known array first becomes able to be assembled as a degraded array,
the array will be assembled even if more devices are still expected.
Signed-off-by: NeilBrown <neilb@suse.de>
install-systemd: systemd/mdmon@.service
$(INSTALL) -D -m 644 systemd/mdmon@.service $(DESTDIR)$(SYSTEMD_DIR)/mdmon@.service
+ $(INSTALL) -D -m 644 systemd/mdadm-last-resort@.timer $(DESTDIR)$(SYSTEMD_DIR)/mdadm-last-resort@.timer
+ $(INSTALL) -D -m 644 systemd/mdadm-last-resort@.service $(DESTDIR)$(SYSTEMD_DIR)/mdadm-last-resort@.service
uninstall:
rm -f $(DESTDIR)$(MAN8DIR)/mdadm.8 $(DESTDIR)$(MAN8DIR)/mdmon.8 $(DESTDIR)$(MAN4DIR)/md.4 $(DESTDIR)$(MAN5DIR)/mdadm.conf.5 $(DESTDIR)$(BINDIR)/mdadm
--- /dev/null
+[Unit]
+Description=Activate md array even though degraded
+DefaultDependencies=no
+
+[Service]
+Type=oneshot
+ExecStart=/sbin/mdadm --run /dev/%i
--- /dev/null
+[Unit]
+Description=Timer to wait for more drives before activating degraded array.
+DefaultDependencies=no
+
+[Timer]
+OnActiveSec=30
# remember you can limit what gets auto/incrementally assembled by
# mdadm.conf(5)'s 'AUTO' and selectively whitelist using 'ARRAY'
-ACTION=="add", RUN+="/sbin/mdadm --incremental $devnode --offroot"
+ACTION=="add", IMPORT{program}="/sbin/mdadm --incremental --export $devnode --offroot"
+ACTION=="add", ENV{MD_STARTED}=="*unsafe*", ENV{MD_FOREIGN}=="no", ENV{SYSTEMD_WANTS}+="mdadm-last-resort@$env{MD_DEVICE}.timer"
ACTION=="remove", ENV{ID_PATH}=="?*", RUN+="/sbin/mdadm -If $name --path $env{ID_PATH}"
ACTION=="remove", ENV{ID_PATH}!="?*", RUN+="/sbin/mdadm -If $name"