kexec-tools/dracut-kdump-emergency.target

#  This file is part of systemd.
#
#  systemd is free software; you can redistribute it and/or modify it
#  under the terms of the GNU Lesser General Public License as published by
#  the Free Software Foundation; either version 2.1 of the License, or
#  (at your option) any later version.

[Unit]
Description=Emergency Mode
Documentation=man:systemd.special(7)
Requires=emergency.service
After=emergency.service
AllowIsolate=yes
IgnoreOnIsolate=yes
kdump-emergency: fix "Transaction is destructive" emergency failure 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="] 2017-03-27 04:07:32 +00:00			`# This file is part of systemd.`
			`#`
			`# systemd is free software; you can redistribute it and/or modify it`
			`# under the terms of the GNU Lesser General Public License as published by`
			`# the Free Software Foundation; either version 2.1 of the License, or`
			`# (at your option) any later version.`

			`[Unit]`
			`Description=Emergency Mode`
			`Documentation=man:systemd.special(7)`
			`Requires=emergency.service`
			`After=emergency.service`
			`AllowIsolate=yes`
			`IgnoreOnIsolate=yes`