[kwlug-disc] Inconsistency in systemd ...

[Khalid Baheyeldin]

Thanks for the pointers.

This page was useful.

https://wiki.archlinux.org/index.php/Power_management

The root-suspend.service and root-resume.service scripts in it improve
things. I made it call the mount and unmount scripts that I have written,
instead of just killing the sshfs process.

But the symptoms remain the same:  one files system will be unmounted and
the other will remain mounted. No mounting when returning from sleep (maybe
network is still not up), wrong messages in syslog about file system being
busy (yet,I know for sure nothing is using it).

I have given up, and went back to mounting and unmounting manually.

On Fri, May 26, 2017 at 6:43 PM, Ronald Barnes <ron at ronaldbarnes.ca> wrote:

> Khalid Baheyeldin wrote on 2017-05-26 05:13 PM:
>
> Yes, this is another systemd rant ...
>>
>> As many of you know, most distros have been adding more and more
>> systemd integration with their new releases.
>>
>
> True.  This bothered me.  Until I realized Arch Linux adopted it.  And
> judging from their wiki, they know what they're doing (it seems to me).
>
>
>
> Here is the use case: When I put the laptop to sleep, I want to
>> unmount the remote file systems [snip]
>>
>> But in Ubuntu 16.04 and its variants, this no longer works. Why?
>> Because systemd decided that this is not the right way to do things,
>> and instead the script has to be in /lib/systemd/system-sleep/.
>>
>
> From
> https://www.freedesktop.org/software/systemd/man/systemd-sus
> pend.service.html
> is this:
>
> Note that scripts or binaries dropped in
>> /usr/lib/systemd/system-sleep/ are intended for local use only and
>> should be considered hacks. If applications want to react to system
>> suspend/hibernation and resume, they should rather use the Inhibitor
>> interface.
>>
>
> Have a look at that, and the Inhibitor interface: prevents sleep midway
> through burning an optical drive, for example.
>
>
>
>> WHAT? A SCRIPT you say? You mean A SHELL SCRIPT? Wasn't the whole
>> rationale of systemd is to not write scripts because SCRIPTS ARE BAD,
>> and use unit file directives?
>>
>
> From a quick search, it seems unit files are the recommended way:
>
> https://wiki.archlinux.org/index.php/Power_management#Power_
>> management_with_systemd
>>
>
>
>>
>> Suspend and hibernate
>>
>> systemd provides commands for suspend to RAM, hibernate and a hybrid
>> suspend using the kernel's native suspend/resume functionality. There
>> are also mechanisms to add hooks to customize pre- and post-suspend
>> actions. Note: systemd can also use other suspend backends (such as
>> Uswsusp or TuxOnIce), in addition to the default kernel backend, in
>> order to put the computer to sleep or hibernate. See Uswsusp#With
>> systemd for an example.
>>
>> systemctl suspend should work out of the box, for systemctl
>> hibernate to work on your system you need to follow the instructions
>> at Suspend and hibernate#Hibernation.
>>
>
> It does appear that one can hook in to the suspend sequence.
>
>
>
>
> WHAT? So NO ORDER OF EXECUTION? NO DEPENDENCIES and before/after
>> order? Wasn't these the rationale for systemd in the first place?
>> There is no way to specify order of execution, or prerequisites.
>>
>
> From Arch wiki:
>
> /etc/systemd/system/suspend at .service
>>
>> [Unit] Description=User suspend actions Before=sleep.target
>>
>
> and
>
> /etc/systemd/system/resume at .service
>>
>> [Unit] Description=User resume actions After=suspend.target
>>
>
>
>
> The systemd developers contradicted themselves here, twice.
>>
>
> Have a look at the unit files, that's their recommendation and it seems
> to work okay.
>
>
> And there are annoying side effects too. Sometimes, the Network
>> Widget in the notification area will be lost, and instead of a WiFi
>> icon, it would show the up/down arrow icon, and clicking on it will
>> not show the current connection, or other Wifi access points
>> available. This is probably because wpa_supplicant died or
>> something.
>>
>
> That's annoying.  Try: systemctl restart network-manager.service
>
>
> Keep us posted on your progress; be happy to hear this works or willing
> to try to get it working.
>
>
> Regards,
>
> rb
>



-- 
Khalid M. Baheyeldin
2bits.com, Inc.
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