Re: System unusably slow after Debian upgrade.
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
- 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.
I saw this precise behavior on a couple of upgraded Debian boxes.