Re: System unusably slow after Debian upgrade.

[Tixy <tixy@yxit.co.uk>]

On Fri, 2020-02-28 at 06:45 -0500, Dan Ritter wrote:
> Dan Ritter wrote: 
> > Go to /etc/nsswitch.conf
> > 
> > If these lines look like this
> > 
> > passwd:         compat systemd
> > group:          compat systemd
> > shadow:         compat systemd
> > 
> > remove the systemd references.
> > 
> > If performance improves immensely immediately after the edit,
> > that was the problem.
> 
> On re-reading the original complaint, I am nearly convinced that
> this is the problem.
> 
> A ridiculously decelerated gzip is evidence of one of the
> following:
> 
> - CPU throttling
> - disk errors
> - something interfering with the disk reading or writing
> 
> The failure mode for systemd providing nsswitch services is a
> huge delay of lookup times for every passwd or group entry
> which affects every file open. gzip opens a lot of files.

Huh? You mean a glibc goes to talk to systemd on every fopen? Surely,
file access permissions are handled by the kernel, otherwise you could
just bypass checks by directly using the 'open' syscall.

-- 
Tixy