systemd: add weekly and monthly scrub timers

Timers can be enabled as follows:

systemctl enable [email protected] --now
systemctl enable [email protected] --now

Each timer will pull in zfs-scrub@${poolname}.service, which is not
schedule-specific.

Added PERIODIC SCRUB section to zpool-scrub.8.

Reviewed-by: Richard Laager <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Georgy Yakovlev <[email protected]>
Closes #12193 

5 files changed, 43 insertions, 1 deletions

diff --git a/etc/systemd/system/.gitignore b/etc/systemd/system/.gitignore
index efada54ad..4813c65a2 100644
--- a/etc/systemd/system/.gitignore
+++ b/etc/systemd/system/.gitignore
@@ -1,3 +1,4 @@
 *.service
 *.target
 *.preset
+*.timer
diff --git a/etc/systemd/system/Makefile.am b/etc/systemd/system/Makefile.am
index c374a52ac..5e65e1db4 100644
--- a/etc/systemd/system/Makefile.am
+++ b/etc/systemd/system/Makefile.am
@@ -12,7 +12,10 @@ systemdunit_DATA = \
 	zfs-volume-wait.service \
 	zfs-import.target \
 	zfs-volumes.target \
-	zfs.target
+	zfs.target \
+	[email protected] \
+	[email protected] \
+	[email protected]
 
 SUBSTFILES += $(systemdpreset_DATA) $(systemdunit_DATA)
 
diff --git a/etc/systemd/system/[email protected] b/etc/systemd/system/[email protected]
new file mode 100644
index 000000000..903068468
--- /dev/null
+++ b/etc/systemd/system/[email protected]
@@ -0,0 +1,12 @@
+[Unit]
+Description=Monthly zpool scrub timer for %i
+Documentation=man:zpool-scrub(8)
+
+[Timer]
+OnCalendar=monthly
+Persistent=true
+RandomizedDelaySec=1h
+Unit=zfs-scrub@%i.service
+
+[Install]
+WantedBy=timers.target
diff --git a/etc/systemd/system/[email protected] b/etc/systemd/system/[email protected]
new file mode 100644
index 000000000..ede699500
--- /dev/null
+++ b/etc/systemd/system/[email protected]
@@ -0,0 +1,12 @@
+[Unit]
+Description=Weekly zpool scrub timer for %i
+Documentation=man:zpool-scrub(8)
+
+[Timer]
+OnCalendar=weekly
+Persistent=true
+RandomizedDelaySec=1h
+Unit=zfs-scrub@%i.service
+
+[Install]
+WantedBy=timers.target
diff --git a/etc/systemd/system/[email protected] b/etc/systemd/system/[email protected]
new file mode 100644
index 000000000..bebe91d74
--- /dev/null
+++ b/etc/systemd/system/[email protected]
@@ -0,0 +1,14 @@
+[Unit]
+Description=zpool scrub on %i
+Documentation=man:zpool-scrub(8)
+Requires=zfs.target
+After=zfs.target
+ConditionACPower=true
+ConditionPathIsDirectory=/sys/module/zfs
+
+[Service]
+ExecStart=/bin/sh -c '\
+if @sbindir@/zpool status %i | grep "scrub in progress"; then\
+exec @sbindir@/zpool wait -t scrub %i;\
+else exec @sbindir@/zpool scrub -w %i; fi'
+ExecStop=-/bin/sh -c '@sbindir@/zpool scrub -p %i 2>/dev/null || true'