In RHEL6, vmcore file was created if panic occurred during shutdown. This was very useful for analyzing problems during the shutdown sequence. However, in RHEL7, vmcore will not be created after kdump service is stopped. This will make it very difficult to solve problems during shutodwn. The reason why kdump fails to dump vmcore is kdump is stopped too early during the power is off. If add "DefaultDependencies=no" to the [Unit] of kdump.service , kdump will not be stopped by systemd after shutdown command. The manpage of systemd.unit about the DefaultDependencies: If true, (the default), a few default dependencies will implicitly be created for the unit. The actual dependencies created depend on the unit type. For example, for service units, these dependencies ensure that the service is started only after basic system initialization is completed and is properly terminated on system shutdown. The manpage about basic.target: A special target unit covering basic boot-up. systemd automatically adds dependencies of the types Requires= and After= for this target unit to all services (except for those with DefaultDependencies=no). Usually this should pull-in all mount points, swap devices, sockets, timers, and path units and other basic initialization necessary for general purpose daemons. So "DefaultDependencies=no" can keep kdump not stopped too early. But to make it start when power on, add After=basic.target will be better. The systemd-devel mailed to me: using DefaultDependencies=no but also After=basic.target will make sure the service isn't started too early (but kept until systemd's final process killing spree). Signed-off-by: Chao Fan <cfan(a)redhat.com&gt; --- kdump.service | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kdump.service b/kdump.service index 24c1386..5144597 100644 --- a/kdump.service +++ b/kdump.service @@ -1,6 +1,7 @@ [Unit] Description=Crash recovery kernel arming -After=network.target network-online.target remote-fs.target +After=network.target network-online.target remote-fs.target basic.target +DefaultDependencies=no [Service] Type=oneshot -- 2.1.0 _______________________________________________ kexec mailing list kexec(a)lists.fedoraproject.org https://lists.fedoraproject.org/mailman/listinfo/kexec

Minfei On 05/26/15 at 01:32pm, Minfei Huang wrote: > If you can add just one blank line, instead of multi-lines, I think it > is better. Since you are maintaining Fedora kexec-tools, what do you wnat Chao to do? resend the patch or you just amend it and remove the blank line?

> > Acked-by: Minfei Huang <mhuang(a)redhat.com&gt; > > Thanks > Minfei > > On 05/14/15 at 03:04am, Chao Fan wrote: > > In RHEL6, vmcore file was created if panic occurred during shutdown. This was > > very useful for analyzing problems during the shutdown sequence. > > > > However, in RHEL7, vmcore will not be created after kdump service is stopped. > > This will make it very difficult to solve problems during shutodwn. > > > > The reason why kdump fails to dump vmcore is kdump is stopped too early during > > the power is off. > > > > If add "DefaultDependencies=no" to the [Unit] of kdump.service , kdump will > > not be stopped by systemd after shutdown command. > > > > The manpage of systemd.unit about the DefaultDependencies: > > If true, (the default), a few default dependencies will implicitly be created > > for the unit. The actual dependencies created depend on the unit type. For > > example, for service units, these dependencies ensure that the service is > > started only after basic system initialization is completed and is properly > > terminated on system shutdown. > > > > > > The manpage about basic.target: > > A special target unit covering basic boot-up. > > systemd automatically adds dependencies of the types Requires= and After= for > > this target unit to all services (except for those with DefaultDependencies=no). > > Usually this should pull-in all mount points, swap devices, sockets, timers, > > and path units and other basic initialization necessary for general purpose > > daemons. > > > > > > So "DefaultDependencies=no" can keep kdump not stopped too early. But to make > > it start when power on, add After=basic.target will be better. > > The systemd-devel mailed to me: using DefaultDependencies=no but also > > After=basic.target will make sure the service isn't started too early (but kept > > until systemd's final process killing spree). > > > > > > > > > > > > Signed-off-by: Chao Fan <cfan(a)redhat.com&gt; > > --- > > kdump.service | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/kdump.service b/kdump.service > > index 24c1386..5144597 100644 > > --- a/kdump.service > > +++ b/kdump.service > > @@ -1,6 +1,7 @@ > > [Unit] > > Description=Crash recovery kernel arming > > -After=network.target network-online.target remote-fs.target > > +After=network.target network-online.target remote-fs.target basic.target > > +DefaultDependencies=no > > > > [Service] > > Type=oneshot > > -- > > 2.1.0 > > _______________________________________________ > > kexec mailing list > > kexec(a)lists.fedoraproject.org > > https://lists.fedoraproject.org/mailman/listinfo/kexec > _______________________________________________ > kexec mailing list > kexec(a)lists.fedoraproject.org > https://lists.fedoraproject.org/mailman/listinfo/kexec > >