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[QFX5e] How to collect lcmd.log on devices running Junos OS 18.1R1 or later



Article ID: KB36343 KB Last Updated: 10 Dec 2020Version: 1.0

This article describes how to collect lcmd.log, which is useful to troubleshoot hardware-related issues on QFX5e platform.

Note: The article is applicable to the QFX5e platform such as QFX5110 and QFX5210 that are running Junos OS 18.1R1 or later releases.



On QFX Series switch, lcmd.log is located in the /var/log directory of the host OS. However, on a QFX5e platform running Junos OS release 18.1R1 or later, the location of lcmd.log has changed.

On QFX5e, the LXC (Linux container) design has been modified starting from Junos OS 18.1R1 release. Before this modification, the lcmd daemon was running on the host OS, but lcmd is spawned on LXC after the modification.



To collect lcmd.log on QFX5e devices, which are running Junos OS 18.1R1 or later releases, use the following method:

  1. Log in to the host shell. (Remember to log in to Junos OS as root user in advance.)

root@qfx5110> request app-engine host-shell
  1. Check the dcpfe that is running, whether dcpfe0 or dcpfe1.

root@qfx5110:~# lxc-ls --active
  1. Copy lcmd.log from dcpfe and put it in the /var/log/ directory on the host OS.

In case of dcpfe0:

root@qfx5110-node:~# scp /var/log/lcmd-dcpfe.log

In case of dcpfe1:

root@qfx5110-node:~# scp /var/log/lcmd-dcpfe.log
  1. On Junos OS, copy lcmd-dcpfe.log from the host OS to the /var/tmp directory.

root@qfx5110> request app-engine file-copy from-jhost lcmd-dcpfe.log to-vjunos /var/tmp log
  1. Collect /var/tmp/lcmd-dcpfe.log on Junos OS and provide it to Support.



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