Re: Removing systemd from Buster: everything gets slow

[Dan Ritter <dsr@randomstring.org>]

Reco wrote: 
> 	Hi.
> 
> On Wed, Nov 06, 2019 at 12:02:04PM -0500, Dan Ritter wrote:
> > Reco wrote: 
> > > On Tue, Nov 05, 2019 at 10:13:35PM -0500, Dan Ritter wrote:
> > > > If you are removing systemd from a Buster installation, and upon
> > > > reboot everything is ridiculously slow:
> > > > 
> > > > Check for the presence of "systemd" options in /etc/nsswitch.conf.
> > > 
> > > I'm curious. Which libnss-* package failed to remove itself from
> > > nsswitch.conf?
> > 
> > Looks like libnss-systemd
> 
> That's interesting. libnss-systemd ships a valid postrm script that's
> supposed to do just that - removing "systemd" entries from
> nsswitch.conf ($module=systemd, $file=/etc/nsswitch.conf):
> 
>     # we must remove possible [foo=bar] options as well
>     sed -i -r "/(passwd|group):/ s/[[:space:]]+$module\b([[:space:]]*\[[^]]*\])*//" $file
> 
> But:
> 
> 1) postrm script bails if it finds that libnss-systemd is still
> installed, but for another architecture.
> 
> 2) It invokes "sed", not "/bin/sed", and that's another possible reason
> for such failure - locally installed /usr/local/bin/sed which does not
> understand "-i" option or misinterprets that regexp.
> 
> 
> I suggest you to file a bug against libnss-systemd. They use perl in
> postinst already, they might use it in postrm as well.

These might well be bugs, but they seem unlikely to apply here:
it was a fresh Buster install on a new machine, only AMD64
arch, and no locally installed anything yet.

I believe this is the second time I've seen it, though -- I have
a very old laptop that I used as an trial Buster install,
and I had ascribed the terrible slowdowns to some bit of failing
hardware. I should pull that off the shelf and see if it's
libnss-systemd still being installed and enabled in
nsswitch.conf.

Thanks.

-dsr-