[systemd-devel] Emergency mode if non-critical /etc/fstab entries are missing

[Sergei Franco]

>From further reading of documentation, please correct me if I am wrong, one
way (not sure if correct) to start SSH during emergency mode is to edit
/etc/systemd/system/sshd.service and modify:

WantedBy=multi-user.target

to

WantedBy=multi-user.target emergency.target

Do I need to do anything with networking service or systemd will figure
dependency of SSH service automatically? Any reason why emergency mode is
not running SSH by default?

Sergei.


On 26 September 2016 at 13:37, Sergei Franco <sergei.franco at gmail.com>
wrote:

> I wasn't aware of emergency.target existence (systemd is new to me).
> What would be correct way to automatically start networking/ssh in
> emergency mode?
>
> The only thing I could find is this bug report:
> https://bugzilla.redhat.com/show_bug.cgi?id=1213781
>
>
> Sergei.
>
>
>
>
>
> On 26 September 2016 at 13:09, Dave Reisner <d at falconindy.com> wrote:
>
>> On Mon, Sep 26, 2016 at 11:35:51AM +1300, Sergei Franco wrote:
>> > Thank you for your quick reply.
>> >
>> > I just tested this scenario on Ubuntu 12.04LTS (with upstart) and it
>> > present the following message:
>> >
>> > The disk drive for /data is not ready yet or not present.
>> > keys:Continue to wait, or Press S to skip mounting or M for manual
>> recovery
>> >
>> > So it is not as big difference as I initially thought, except it is much
>> > easier to deal with by simply pressing S, while I believe there is no
>> > such option for systemd (it would be nice).
>>
>> Making bootup potentially interactive in this manner is strictly worse
>> than dumping you into emergency mode. At least with emergency mode, you
>> might be able to add dependencies to emergency.target such that, for
>> example, an sshd comes up and an admin can login to the remote box.
>> How's this supposed to work with a random prompt which must be accessed
>> on /dev/console?  Enforce that everyone has some sort of out of band
>> console?
>>
>> Unclear why you consider this a superior design decision...
>>
>> > So in future for non crucial disks I will use nofail.
>> >
>> > Best regards.
>> >
>> > Sergei.
>> >
>> > P.S. As advised I have replied to correct address.
>> >
>> > On 26 September 2016 at 11:30, Reindl Harald <h.reindl at thelounge.net>
>> wrote:
>> >
>> >     if you post somehting to a mailing-list and you get a response on
>> the list
>> >     POST REPLIES TO THE LIST - *period*
>> >
>> >     Am 26.09.2016 um 00:28 schrieb Sergei Franco:
>> >
>> >         Thank you for your quick reply.
>> >
>> >         I just tested this scenario on Ubuntu 12.04LTS (with upstart)
>> and it
>> >         present the following message:
>> >
>> >         The disk drive for /data is not ready yet or not present.
>> >         keys:Continue to wait, or Press S to skip mounting or M for
>> manual
>> >         recovery
>> >
>> >         So it is not as big difference as I initially thought, except
>> it is
>> >         much
>> >         easier to deal with by simply pressing S, while I believe there
>> is no
>> >         such option for systemd (it would be nice).
>> >
>> >         So in future for non crucial disks I will use nofail.
>> >
>> >         Best regards.
>> >
>> >         Sergei.
>> >
>> >         On 26 September 2016 at 10:57, Reindl Harald <
>> h.reindl at thelounge.net
>> >         <mailto:h.reindl at thelounge.net>> wrote:
>> >
>> >
>> >
>> >             Am 25.09.2016 um 23:52 schrieb Sergei Franco:
>> >
>> >                 I am looking at correct way to disable the "feature" of
>> >                 emergency mode
>> >                 when systemd encounters missing block device entires in
>> fstab.
>> >
>> >                 For example:
>> >
>> >                 the following entry is in /etc/fstab:
>> >                 UUID=d4a23034-8cbe-44b3-92a5-3d38e1816eff /data
>>
>> >          xfs
>> >                 defaults        0       0
>> >
>> >                 If the drive (d4a23034-8cbe-44b3-92a5-3d38e1816eff)
>> has been
>> >                 detached
>> >                 and machine rebooted it stops booting with Emergency
>> mode, even
>> >                 though
>> >                 the /data is not crucial for boot
>> >
>> >
>> >             RTFM - when you don't say "nofail" it's ecpected to be
>> crucial
>> >
>> >             your entry says it's crucial
>> >
>> >             http://unix.stackexchange.com/
>> questions/53456/what-is-the-di
>> >         fference-between-nobootwait-and-nofail-in-fstab
>> >             <http://unix.stackexchange.com/questions/53456/what-is-the-
>> >         difference-between-nobootwait-and-nofail-in-fstab>
>> >
>> >
>> >
>> >
>>
>> > _______________________________________________
>> > systemd-devel mailing list
>> > systemd-devel at lists.freedesktop.org
>> > https://lists.freedesktop.org/mailman/listinfo/systemd-devel
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/systemd-devel/attachments/20160926/f0cfcc16/attachment-0001.html>