Comment 0 for bug 1426023

Revision history for this message
Scott Moser (smoser) wrote :

If i launch a new cloud instance, and then ssh to it, my ssh login blocks, stopping me from doing useful work while '/usr/lib/update-notifier/apt-check' runs.

By far, the biggest offender of this slow login is /usr/lib/update-notifier/apt-check.
To demonstrate, a fresh cloud instance on azure.

## ssh to the instance and run a non-interactive command:
$ time ssh $cloudhost /bin/true
real 0m5.066s
user 0m0.045s
sys 0m0.004s

## ssh in and disable updates-available so it wont run at all
$ ssh $cloudhost sudo chmod -x /etc/update-motd.d/90-updates-available
$ time ssh $cloudhost /bin/true
real 0m2.459s
user 0m0.026s
sys 0m0.015s

## so disabling that bought us 2.5 seconds back.

## How about entirely disabling update-motd
$ ssh $cloudhost cp /etc/pam.d/sshd /etc/pam.d/sshd.dist
$ ssh $cloudhost "sudo sed -i '/^[^#].*pam_motd/s/^/#/' /etc/pam.d/sshd
$ time ssh $cloudhost /bin/true
real 0m0.650s
user 0m0.041s
sys 0m0.004s

Note, that these things happen even for non-interactive logins, where the message of the day is completely swallowed. Automation tools suffer this ever time they ssh to a ubuntu system.

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: update-notifier-common 3.157
ProcVersionSignature: User Name 3.16.0-30.40-generic 3.16.7-ckt3
Uname: Linux 3.16.0-30-generic x86_64
ApportVersion: 2.14.7-0ubuntu8.2
Architecture: amd64
Date: Thu Feb 26 16:27:02 2015
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: update-notifier
UpgradeStatus: No upgrade log present (probably fresh install)