We met a problem that the kdump emergency service failed to
start when the target dump timeout(we passed "rd.timeout=30"
to kdump), it reported "Transaction is destructive" messages:
[ TIME ] Timed out waiting for device dev-mapper-fedora\x2droot.device.
[DEPEND] Dependency failed for Initrd Root Device.
[ SKIP ] Ordering cycle found, skipping System Initialization
[DEPEND] Dependency failed for /sysroot.
[DEPEND] Dependency failed for Initrd Root File System.
[DEPEND] Dependency failed for Reload Configuration from the Real Root.
[ SKIP ] Ordering cycle found, skipping System Initialization
[ SKIP ] Ordering cycle found, skipping Initrd Default Target
[DEPEND] Dependency failed for File System Check on /dev/mapper/fedora-root.
[ OK ] Reached target Initrd File Systems.
[ OK ] Stopped dracut pre-udev hook.
[ OK ] Stopped dracut cmdline hook.
Starting Setup Virtual Console...
Starting Kdump Emergency...
[ OK ] Reached target Initrd Default Target.
[ OK ] Stopped dracut initqueue hook.
Failed to start kdump-error-handler.service: Transaction is destructive.
See system logs and 'systemctl status kdump-error-handler.service' for details.
[FAILED] Failed to start Kdump Emergency.
See 'systemctl status emergency.service' for details.
[DEPEND] Dependency failed for Emergency Mode.
This is because in case of root failure, initrd-root-fs.target
will trigger systemd emergency target which requires the systemd
emergency service actually is kdump-emergency.service, then our
kdump-emergency.service starts kdump-error-handler.service with
"systemctl isolate"(see 99kdumpbase/kdump-emergency.service, we
replace systemd's with this one under kdump).
This will lead to systemd two contradictable jobs queued as an
atomic transaction:
job 1) the emergency service gets started by initrd-root-fs.target
job 2) the emergency service gets stopped due to "systemctl isolate"
thereby throwing "Transaction is destructive".
In order to solve it, we can utilize "IgnoreOnIsolate=yes" for both
kdump-emergency.service and kdump-emergency.target. Unit with attribute
"IgnoreOnIsolate=yes" won't be stopped when isolating another unit,
they can keep going as expected in case be triggered by any failure.
We add kdump-emergency.target dedicated to kdump the similar way
as did for kdump-emergency.service(i.e. will replace systemd's
emergency.target with kdump-emergency.target under kdump), and
adds "IgnoreOnIsolate=yes" into both of them.
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Acked-by: Pratyush Anand <panand@redhat.com>
[bhe: improve the patch log about IgnoreOnIsolate="]
Xunlei Pang