Mas DB2 Notes: 2015

Changing hostname of the DB2 server. What updates in DB2 need to be made?

In general you will get the following error if you change your hostname:
db2 => list database directory

System Database Directory

Number of entries in the directory = 1

Database 1 entry:

Database alias                       = UNICADB
Database name                        = UNICADB
Local database directory             = /apps/db2data/unicadb
Database release level               = 10.00
Comment                              =
Directory entry type                 = Indirect
Catalog database partition number    = 0
Alternate server hostname            =
Alternate server port number         =

db2 => drop database UNICADB
SQL1031N The database directory cannot be found on the indicated file system.
SQLSTATE=58031
db2 => quit
DB20000I The QUIT command completed successfully.
[db2inst1@rhel65dbs ~]$ db2 "connect to unicadb"
SQL1031N The database directory cannot be found on the indicated file system.
SQLSTATE=58031
[db2inst1@rhel65dbs ~]$ db2start
09/24/2015 23:36:20     0   0   SQL6048N A communication error occurred during START or STOP DATABASE MANAGER processing.
SQL1032N No start database manager command was issued. SQLSTATE=57019

Here's a good link on what to do. And another link to troubleshoot.

For me, here's what I did:

0. Login as db2inst1 and shutdown
db2stop

1. Login as root:
[root@rhel65dbs sqllib]# db2set -g DB2SYSTEM=rhel65dbs.local.com
[root@rhel65dbs sqllib]# db2set -g
DB2SYSTEM=rhel65dbs.local.com
DB2INSTDEF=db2inst1
DB2ADMINSERVER=dasusr1
[root@rhel65dbs sqllib]# uname -a
Linux rhel65dbs.local.com 2.6.32-431.el6.x86_64 #1 SMP Sun Nov 10 22:19:54 EST 2013 x86_64 x86_64 x86_64 GNU/Linux

2. Locate db2nodes.cfg in one of the following directories:

UNIX/Linux:

<db2 instance home directory>/sqllib/db2nodes.cfg

3. In the db2nodes.cfg file change <current hostname> to <new hostname>.

4. Login as db2inst1 and verify:

[root@rhel65dbs sqllib]# su - db2inst1
[db2inst1@rhel65dbs ~]$ db2set -g
DB2SYSTEM=rhel65dbs.local.com
DB2INSTDEF=db2inst1
DB2ADMINSERVER=dasusr1

5. Startup and connect:

[root@rhel65dbs sqllib]# su - db2inst1
[db2inst1@rhel65dbs ~]$ db2start
09/25/2015 00:09:06     0   0   SQL1063N DB2START processing was successful.
SQL1063N DB2START processing was successful.
[db2inst1@rhel65dbs ~]$ db2 "connect to unicadb"

   Database Connection Information

Database server        = DB2/LINUXX8664 10.5.3
SQL authorization ID   = DB2INST1
Local database alias   = UNICADB

1. LIST DATABASE DIRECTORY

db2 => list database directory

System Database Directory

Number of entries in the directory = 1

Database 1 entry:

Database alias                       = UNICADB
Database name                        = UNICADB
Local database directory             = /apps/db2data/unicadb
Database release level               = 10.00
Comment                              =
Directory entry type                 = Indirect
Catalog database partition number    = 0
Alternate server hostname            =
Alternate server port number         =

2. LIST ACTIVE DATABASES
    (An active database is available for connection and use by any application)

db2 => list active database
SQL0104N An unexpected token "database" was found following "ACTIVE".
Expected tokens may include: "DATABASES". SQLSTATE=42601
db2 => list active databases

                           Active Databases

Database name                              = UNICADB
Applications connected currently           = 1
Database path                              = /apps/db2data/unicadb/db2inst1/NODE0000/SQL00001/MEMBER0000/

Mas DB2 Notes

Thursday, September 24, 2015

Changing hostname of the DB2 server. What updates in DB2 need to be made?

A useful list of IBM DB2 commands

List all databases in an instance