What are the configuration requirements of the member and CF hostnames?

Db2® pureScale® does not impose specific rules on the cluster caching facility (CF) or member hostnames as long as the hostname values follow what is in the Operating System host file and the hostname resolution is configured properly.

On all pureScale-supported Linux and AIX platforms, use /etc/hosts as the reference for OS hostname values. The hostnames of CFs and members should follow the FQDN or alias of the OS hostname values. Also, the OS hostname configuration for all nodes in the cluster should be the same.

/etc/hosts follows this format.

<IP_address>         <FQDN>         <alias>
eg.
2.2.2.2           svtps01.torolab.ibm.com           svtps01
1.1.0.1           svtps01-ens4.torolab.ibm.com           svtps01-ens4
1.1.1.1           svtps01-ens4d1.torolab.ibm.com           svtps01-ens4d1
...

When CF/member hostnames are needed, such as when running the db2icrt command, use the hostname values found in /etc/hosts.

./db2icrt -d -m <host_name> -mnet <interface1_name>,<interface2_name> -cf <host_name> -cfnet < interface1_name >,< interface2_name > -instance_shared_dir <shared_dir> -tbdev <tb_disk> -u <fenced_id> <instance_name>
eg.
./db2icrt -d -m svtps02 -mnet svtps02-ens4,svtps02-ens4d1 -cf svtps01 -cfnet svtps01-ens4,svtps01-ens4d1 -instance_shared_dir /db2sd_20190000000000 -tbdev /dev/dm-1 -u instance instance

In addition, implementing a fast hostname resolution scheme is essential in building a well-performing Db2 pureScale cluster.

Refer to Hostname resolution configuration (Linux) for the hostname resolutions scheme on Linux.

Refer to Hostname resolution configuration (AIX) for the hostname resolutions scheme on AIX.

Lastly, SSH must work with both the FQDN and aliases of the hostname values.

ssh <instance_name>@<FQDN>
ssh <instance_name>@<alias>
eg.
ssh instance@svtps01.torolab.ibm.com
ssh instance@ svtps01