IBM DB2 manual Remote shell, Users and groups in a partitioned database environment

Other file system technologies that provide concurrent access to a common set of files can also be used in creating the instance home directory in a DB2 partitioned database system. The IBM General Parallel File System™ (GPFS™) is an example. It is a high performance scalable file management solution available on both AIX and Linux. For more information about GPFS, refer to:

http://www.ibm.com/systems/clusters/software/gpfs/index.html

Remote shell

For a partitioned database system on the UNIX/Linux platforms, a remote shell utility is required to issue commands to every partition. DB2 9.5 supports two remote utilities:

￿rsh

￿ssh

Remote Shell (rsh) is a traditional shell utility that has been supported by DB2 for many years. It is the default shell tool used by DB2 after the installation. It allows the user to execute commands from another computer over the network. But rsh could be considered an insecure utility because it does not provide strong encryption when sending information over a network.

Security Shell (ssh) could be taken as an improved version of remote shell. It uses public-key technology to encrypt and decrypt messages and to authenticate a remote user who requests to access a local machine. It is just as flexible as rsh. Support for ssh was introduced in DB2 V8.2.

Note: Unlike UNIX and Linux, we do not have to configure remote shell for DB2 on Windows. There is a DB2 service automatically installed to support remote DB2 command executions. It is called DB2 Remote Command Server.

Users and groups in a partitioned database environment

There is not much difference between a multi-partitioned database and a single-partitioned database in regard to users and groups. Three users and their groups have to be created on each participating machine. For the instance user and the fenced user, not only the name of the user or group, but also the user ID or the group ID, must be identical on each machine.

For the Administration user, it also has to be created on each participating computer, not just the instance owning one, to allow administrative tasks to be performed on that computer.

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