Additional installation considerations (Linux)
Before you install data server products on Linux® operating systems, ensure that the system you choose meets the
necessary operating system, hardware, software, and communications requirements. You can use the
db2prereqcheck command to check whether your system meets the prerequisites
for the installation.
For the most up-to-date installation requirements for data server products, see System requirements for IBM® Db2® for Linux, UNIX, and Windows. This techdoc uses IBM Software Product Compatibility Reports (SPCR). With the SPCR tool, you can locate and find complete lists of supported operating systems, system requirements, prerequisites, and other supported software for these database products.
- If you are planning to install the IBM Db2 pureScale® Feature, different installation prerequisites are required. See the Installing the Db2 pureScale Feature topic.
- For the most up-to-date requirements for Db2 database products, see System requirements for IBM® Db2® for Linux, UNIX, and Windows .
Multithreaded architecture limitations
- Private memory for agent threads is allocated within a single process. The aggregate of all private memory allocations for database agents might not fit in a single process memory space.
- Support for multiple databases is limited because all database shared memory segments for all databases are allocated in a single process. You might need to reduce the memory usage for some databases to activate all databases successfully at the same time. However, the database manager performance might be impacted. Another alternative is to create multiple instances and catalog the databases across the instances when you have sufficient system resources to support this configuration.
Make sure that you update your kernel configuration parameters before you install a Db2 database product. The default values for particular kernel parameters might not be sufficient when you run a Db2 database system.
You might also have other products or applications that require Linux system resources. Make sure that you modify the kernel configuration parameters based on the needs of the working environment of your Linux system.
The kernel configuration parameters are set in /etc/sysctl.conf.
For more information about the sysctl command, see your operating system manual.
- libpam.so.0 (32-bit) is required for Db2 database servers to run 32-bit non-SQL routines and JDBC type 2 driver applications in 32-bit JDK.
- libpam.so.0 is required by IBM data server clients for Db2 user authentication.
- libaio.so.1 is required for Db2 database servers that use asynchronous I/O.
- libstdc++.so.6 is required for Db2 database servers and clients.
- libstdc++33 and libstdc++43 are required for SLES 11.
- ksh (AT&T Korn shell) is required for all Db2 database systems. mksh (MirBSD Korn Shell) or lksh (Legacy Korn Shell) are not supported.
|libaio||Contains the asynchronous library that is required for data servers.|
|libstdc++||Contains libstdc++.so.6 that is not required for Linux on POWER® or SLES 11.|
|libxlc||Contains libibmc++.so.1 (64 bit only) that is required for Linux on POWER little endian.|
|ksh||AT&T Korn Shell|
- A remote shell utility is required for partitioned database systems. Db2 database systems
support the following remote shell utilities:
If you choose to use the rsh remote shell utility, inetd (or xinetd) must be installed and running as well. If you choose to use the ssh remote shell utility, you need to set the DB2RSHCMD communication variable immediately after the Db2 installation is complete. If this registry variable is not set, rsh is used. In addition, ensure that no messages that are triggered by the profile or messages such as those in /etc/motd are displayed if the logging in session is not an interactive shell. Tools such as db2ival might be disrupted otherwise.
- The nfs-utils Network File System support package is required for partitioned database systems.
All required packages must be installed and configured prior to the Db2 database system setup. For general Linux information, see your Linux distribution documentation.
|openssh||This package contains a set of server programs, which allow users to run commands on (and from) remote computers via a Secure Shell. This package is not required if you use the default configuration of Db2 database systems with rsh.|
|rsh-server||This package contains a set of server programs that allow users to run commands on remote computers, login in to other computers, and copy files between computers (rsh, rexec, rlogin, and rcp). This package is not required if you configure data servers to use ssh.|
|nfs-utils||Network File System support package. It allows access to local files from remote computers.|
|/Applications/Internet||openssh||This package contains a set of client programs, which allow users to run commands on a remote computer via a Secure Shell. This package is not required if you use the default configuration of Db2 database systems with rsh.|
|/System Environment/Daemons||openssh-server\||This package contains a set of server programs that allow users to run commands from a remote computer via a Secure Shell. This package is not required if you use the default configuration of Db2 database systems with rsh.|
|/System Environment/Daemons||rsh-server||This package contains a set of programs, which allow users to run commands on a remote computer. Required for partitioned database environments. This package is not required if you configure Db2 database systems to use ssh.|
|/System Environment/Daemons||nfs-utils||Network File System support package. It allows access to local files from remote computers.|
- (Client and Server) To use Kerberos authentication, install the Linux krb5 Kerberos support via the operating system Kerberos packages.
- An X Window System software capable of rendering a graphical user interface is required in the
- You want to use the Db2 Setup wizard to install a Db2 database product on Linux or UNIX operating systems, or
- You want to use graphical tools on Linux for x86 and Linux on AMD 64/EM64T.
- Micro Focus does not offer support for any of its COBOL compiler products on SLES 11.
- If you plan on using transparent Lightweight Directory Access Protocol (LDAP) on RHEL 5, you must install nss_ldap-253-35.el5 or later.
Security-enhanced Linux considerations
On RHEL systems, if Security-enhanced Linux (SELinux) is enabled and in enforcing mode, the installer might fail due to SELinux restrictions.
- Check the /etc/sysconfig/selinux file.
- Run the sestatus command.
- Check the /var/log/messages file for SELinux notices.
- Set it in permissive mode and run the setenforce 0 command as a superuser.
- Modify /etc/sysconfig/selinux and reboot the machine.
If your Db2 database product installs successfully on an RHEL system, Db2 processes will run in the unconfined domain. To assign Db2 processes to their own domains, modify the policy. A sample SELinux policy is provided in the sqllib/samples directory.