Adding communication adapter ports to a CF or member

Cluster caching facilities (CFs) and members support multiple communication adapter ports. Using multiple communication adapter ports provide greater scalability and availability. This task describes how to add a communication adapter port.

Before you begin

About this task

Adding communication adapter ports helps achieve the following goals:
  • Increase bandwidth to handle more requests by using more than one communication adapter port.
  • Enable the adoption of network topologies with multiple switches.


  1. A maximum of four communication adapter ports can be used on each CF or member. Members or CFs may use 1 or 2 ports on a corresponding supported IB or RoCE card for Db2 pureScale instance.
  2. If a member and CF reside on the same physical host (or LPAR), both the CF and member must be configured to use the same communication adapter ports.


To enable additional communication adapter ports:

  1. Attach an extra interconnect cable from the switch to an open communication adapter port on the CF or member.
  2. Configure the IP address and the associated cluster interconnect netname.
  3. Repeat steps 1 - 2 for any additional ports you plan to use.
  4. Log in as the instance owner on a host in the Db2 pureScale instance and stop the CF or member to be updated.
    For example, to stop the CF:
    db2stop CF <id>
    where <id> is the numeric identifier. You can find the numeric identifier in the sqllib/db2nodes.cfg file.
  5. To update the CF or member with the additional cluster interconnect netname configured in the preceding step, log in as the user with root authority and run the db2iupdt -update command on each CF or member with the additional port.
    For example, to update the CF:
    <db2_install_path>/instance/db2iupdt -update -cf <cfHostname> -cfnet <cfnet0,cfnet1> <instanceName>
    For example, to update a member:
    <db2_install_path>/instance/db2iupdt -update -m <memberHostname> -mnet <membernet0,membernet1> <instanceName>

    where <db2_install_path> is where the Db2 product was installed. You can find the installation path by running the db2level command.

  6. Log in as the instance owner on a host in the Db2 pureScale instance and start the CF or member to be updated.
    For example to start the CF:
    db2start CF  <id>
  7. If you updated a CF with an additional cluster interconnect netname, after the netname is added, each member must be stopped and started.


The cluster caching facility or member now communicates through each communication adapter port by using the registered cluster interconnect netname.


Updating a CF and member to use an additional communication adapter port on an InfiniBand network.

  1. Before updating the CF or member, sqllib/db2nodes.cfg contains:
    0   memberhost0    0   membernet0 - MEMBER
    128 cfhost0        0   cfnet0 - CF
    Note: Do not modify db2nodes.cfg directly.
  2. Update the CF and member by running these commands:
    <db2_install_path>/instance/db2iupdt -update -cf cfhost0 -cfnet cfnet0,cfnet1 <instanceName>
    <db2_install_path>/instance/db2iupdt -update -m memberhost0 -mnet membernet0,membernet1 <instanceName>
    After the updates, the db2nodes.cfg contains:
    0   memberhost0    0   membernet0,membernet1 - MEMBER
    128 cfhost0        0   cfnet0,cfnet1 - CF

What to do next

Repeat the same procedure on the secondary CF or other members.