Chapter 2. Downloading log files and diagnostic information using must-gather

Procedure

• Run the must-gather command from the client connected to the OpenShift Container Storage cluster:

  $ oc adm must-gather --image=registry.redhat.io/ocs4/ocs-must-gather-rhel8:v4.8 --dest-dir=<directory-name>

  This collects the following information in the specified directory:

  • All OpenShift Container Storage cluster related Custom Resources (CRs) with their namespaces.
  • Pod logs of all the OpenShift Container Storage related pods.
  • Output of some standard Ceph commands like Status, Cluster health, and others.

Command variations

• If one or more master nodes are not in the Ready state, use --node-name to provide a master node that is Ready so that the must-gather pod can be safely scheduled.

  $ oc adm must-gather --image=registry.redhat.io/ocs4/ocs-must-gather-rhel8:v4.8 --dest-dir=<directory-name> --node-name=<node-name>

• If you want to gather information from a specific time:

  • To specify a relative time period for logs gathered, such as within 5 seconds or 2 days, add /usr/bin/gather since=<duration>:

    $ oc adm must-gather --image=registry.redhat.io/ocs4/ocs-must-gather-rhel8:v4.8 --dest-dir=<directory-name> /usr/bin/gather since=<duration>

  • To specify a specific time to gather logs after, add /usr/bin/gather since-time=<rfc3339-timestamp>:

    $ oc adm must-gather --image=registry.redhat.io/ocs4/ocs-must-gather-rhel8:v4.8 --dest-dir=<directory-name> /usr/bin/gather since-time=<rfc3339-timestamp>

  Replace the example values in these commands as follows:

  <node-name>

  If one or more master nodes are not in the Ready state, use this parameter to provide the name of a master node that is still in the Ready state. This avoids scheduling errors by ensuring that the must-gather pod is not scheduled on a master node that is not ready.

  <directory-name>

  The directory to store information collected by must-gather.

  <duration>

  Specify the period of time to collect information from as a relative duration, for example, 5h (starting from 5 hours ago).

  <rfc3339-timestamp>

  Specify the period of time to collect information from as an RFC 3339 timestamp, for example, 2020-11-10T04:00:00+00:00 (starting from 4am UTC on 11 Nov 2020).