[systemd-devel] [PATCH] fstab-generator: introduce rd.weak_sysroot to bypass failures in sysroot.mount

[Kay Sievers]

On Tue, Jul 30, 2013 at 4:02 PM, Tom Gundersen <teg at jklm.no> wrote:
> On Tue, Jul 30, 2013 at 2:27 PM, WANG Chao <chaowang at redhat.com> wrote:
>> On 07/30/13 at 02:05pm, Tom Gundersen wrote:
>>> On Tue, Jul 30, 2013 at 1:53 PM, WANG Chao <chaowang at redhat.com> wrote:
>>> >  - It's not before initrd-root-fs.target.
>> In case of kdump, 2nd kernel initrd is used to mount non-root local/remote
>> filesystem and dump vmcore there. The kdump script is running right
>> before switch-root and will reboot after saving vmcore.
>>
>> So mounting sysroot isn't quite justified in this case.  But it's still
>> acceptable (since it's readonly mount), as long as it's not keeping
>> systemd from reaching initrd.target (so kdump script can run later).
>
> If you don't have the Before=initrd-root-fs.target it means that
> you'll have a race: sometimes the rootfs will be mounted  before kdump
> does whatever it does, and sometimes it won't. Would an option be to
> not specify a root= at all in your case?

Nothing should make assumptions about root= not specified at the
kernel command line. It is reserved to make auto-discovery by
partition type UUID work.

It needs an explicit value to trigger non-common, non-default behavior;
otherwise things would likely break in the future.

Kay