I’ve written about issues related to “SQL6048N A communication error occurred during START or STOP DATABASE MANAGER processing” before, but I thought I’d add a few short notes.
- Your machine needs to be able to ping itself. If it can’t ping itself, it can’t DB2 itself either.
- The output of hostname, db2set -all, and cat /home/db2inst1/sqllib/db2nodes.cfg needs to match.
If your machine can’t ping itself, cat /etc/hosts. Chances are, you need to add a line like the following:
127.0.0.1 myhostname.mydomain myhostname
If DB2SYSTEM is set to the wrong value, db2set -g DB2SYSTEM=`hostname` will fix it on Linux.
If db2nodes.cfg has the wrong value, overwrite it with the right one.