SQL1041N The maximum number of concurrent databases have already been started

Saw this referenced in a thread on the IBM Connections Community Chat, moderated by the nice Mr Stuart McIntyre ( SocialStu ), and thought it was worth re-posting.

Problem(Abstract)

This technote explains how to resolve an SQL1041N error that can occur when trying to connect to an IBM® DB2® Test Datastore from IBM Rational® TestManager (TM).

Cause

The default number of databases that can be concurrently active (that is, have applications connected to them) is 8.

Resolving the problem

Change the number of databases that can be concurrently active to the desired number. The valid range is 1 to 256.

To change this number:

• Open the DB2 Control Center

• Expand All Systems -> [server name] -> Instances

• Right-click on the instance that you want to change (DB2 instance) and choose Configure Parameter from the pop-up menu

• Scroll down to NUMDB (under Environment)

• Change the value to the desired number

• Restart the DB2 service (Start -> Run -> services.msc)

As Stuart also pointed out, for those of us who (a) prefer command lines or (b) choose not to use DB2 Control Centre or (c) choose not to run DB2 on Windows, the NUMDB parameter can be set via the DB2 CLI: -

$ db2 update database manager configuration using numdb 15
$ db2stop
$ db2start
$ db2 get database manager configuration

( as the DB2 instance owner of the Connections - or other application - databases )