IBM Spectrum Protect normally uses a connection over TCPIP to backup its database. In this article i will show you how to change connection to Shared Memory. Changes has to be made in configuration from server instance and a special dsm.sys.

This option was introduced in version 7.1 of Tivoli Storage Manager.

Server

The serverinstance is configured by a File in home directory which is called dsmserv.opt

The following lines must be added:

COMMMethod  SHAREdmem
SHMPort 1510

The server instance must be restarted for the changes to take effect.

After this you can check with Telnet if the port is opened and reachable.

# telnet localhost 1510
Trying... 
Connected to localhost.
Escape character is '^]'.

At this point only the server side is opened, but database backup uses still TCPIP as commucation method.

Database Backup Client

Database backup uses a special Node called $$_TSMDBMGR_$$, options are stored in a dsm.sys file like a normal Backup-Archive Client.

This special file can be found at the following path:

# AIX 
/opt/tivoli/tsm/server/bin/dbbkapi/dsm.sys

Diese sollte folgenden Inhalt aufweisen: Following lines shoud be in this file:

COMMMethod      SHAREdmem
SHMPort         1510
NODENAME        $$_TSMDBMGR_$$
PASSWORDDIR     <HOME of instance user>
ERRORLOGNAME    <HOME of instance user>/tsmdbmgr.log

Performance

I have expirenced a speedup of 2 times faster than using TCPIP. In addition to that i have opserved that throughput is more constant, there a no slow individual database backups.