Chapter 8. Modifying, displaying, and exporting the corosync.conf file


To set cluster parameters, corosync uses the corosync.conf file. Do not edit corosync.conf directly. Use the pcs interface instead.

Modify corosync.conf parameters, such as token timeouts and logging levels, using pcs. pcs validates input and synchronizes changes across all nodes, ensuring consistency. While some updates apply immediately, modifying core transport settings requires a cluster restart.

Procedure

  • The following command modifies the parameters in the corosync.conf file:

    # pcs cluster config update [transport pass:quotes[transport options]] [compression pass:quotes[compression options]] [crypto pass:quotes[crypto options]] [totem pass:quotes[totem options]] [--corosync_conf pass:quotes[path]]
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  • The following example command udates the knet_pmtud_interval transport value and the token and join totem values:

    # pcs cluster config update transport knet_pmtud_interval=35 totem token=10000 join=100
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Display the contents of the corosync.conf configuration file to verify cluster settings, network parameters, and quorum configuration.

Procedure

  • Display the contents of the corosync.conf file:

    # pcs cluster corosync
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    You can print the contents of the corosync.conf file in a human-readable format with the pcs cluster config command, as in the following example.

    The output for this command includes the UUID for the cluster if the UUID was added manually as described in Identifying clusters by UUID.

    [root@r8-node-01 ~]# pcs cluster config
    Cluster Name: HACluster
    Cluster UUID: ad4ae07dcafe4066b01f1cc9391f54f5
    Transport: knet
    Nodes:
      r8-node-01:
        Link 0 address: r8-node-01
        Link 1 address: 192.168.122.121
        nodeid: 1
      r8-node-02:
        Link 0 address: r8-node-02
        Link 1 address: 192.168.122.122
        nodeid: 2
    Links:
      Link 1:
        linknumber: 1
        ping_interval: 1000
        ping_timeout: 2000
        pong_count: 5
    Compression Options:
      level: 9
      model: zlib
      threshold: 150
    Crypto Options:
      cipher: aes256
      hash: sha256
    Totem Options:
      downcheck: 2000
      join: 50
      token: 10000
    Quorum Device: net
      Options:
        sync_timeout: 2000
        timeout: 3000
      Model Options:
        algorithm: lms
        host: r8-node-03
      Heuristics:
        exec_ping: ping -c 1 127.0.0.1
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8.3. Exporting the corosync.conf file

You can run the pcs cluster config show command with the --output-format=cmd option to display the pcs configuration commands that can be used to recreate the existing corosync.conf file on a different system.

Procedure

  • Export the corosync.conf file:

    [root@r8-node-01 ~]# pcs cluster config show --output-format=cmd
    pcs cluster setup HACluster \
      r8-node-01 addr=r8-node-01 addr=192.168.122.121 \
      r8-node-02 addr=r8-node-02 addr=192.168.122.122 \
      transport \
      knet \
        link \
          linknumber=1 \
          ping_interval=1000 \
          ping_timeout=2000 \
          pong_count=5 \
        compression \
          level=9 \
          model=zlib \
          threshold=150 \
        crypto \
          cipher=aes256 \
          hash=sha256 \
      totem \
        downcheck=2000 \
        join=50 \
        token=10000
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