Additional installation considerations (AIX)

Before you install data server products on AIX® operating systems, ensure that the system you choose meets the necessary operating system, hardware, software, and communications requirements.

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 optional supported software for these database products.

Note: If the minimum operating system requirements were applied using an operating system upgrade rather than using a new operating system installation, you must install I/O completion ports (IOCP) separately. You can obtain the IOCP libraries from the AIX installation CD and configure IOCP on the data server. For a client only installation, IOCP is not required. For more information, see configuring IOCP on AIX.

Software considerations

For application development and runtime considerations, see the topics in Supported programming languages and compilers for database application development.
To download the latest IBM C++ Runtime Environment Components for AIX, see the IBM AIX XL C and C++ support page.
(Clients only) If you plan to use Kerberos Authentication, you require IBM Network Authentication Service client v1.4 or later.
Use the bosboot command to switch to the 64-bit kernel.
To switch to a 64-bit kernel, you require root authority and enter the following commands:
```
   ln -sf /usr/lib/boot/unix_64 /unix
   ln -sf /usr/lib/boot/unix_64 /usr/lib/boot/unix
   bosboot -a
   shutdown -Fr
```
An X Window System software capable of rendering a graphical user interface is required if you want to use the Db2 Setup wizard to install a data server product on Linux or UNIX operating systems.
Live Partition Mobility (LPM) is supported in partitioned database environments with multi physical node configurations.
For details regarding known AIX issues, see Known issues for DB2 for Linux, UNIX and Windows on AIX 5.3, 6.1, 7.1,and 7.2.

Mounting considerations

For root installations of data server products on UNIX operating systems, do not mount your file system with the nosetuid option.

Performance considerations

Memory is allocated to applications using the malloc subsystem. By default, the malloc subsystem uses a single heap, or free memory pool. However, it also provides an optional multiheap capability to allow the use of multiple heaps of free memory, rather than just one. The purpose of providing multiple-heap capability in the malloc subsystem is to improve the performance of threaded applications running on multiprocessor systems.

When the default AIX memory allocation setting is used at higher concurrency levels, it can result in serialization during memory allocation, which can affect throughput. The core of the Db2® database engine allocates private memory using the Db2 memory manager, which adds a layer of caching and high-performing concurrency management on top of the standard AIX malloc subsystem. However, some products integrated within Db2, such as IBM GSKit, interface directly with AIX malloc and are subject to the performance capabilities of the AIX malloc manager setting.

For instructions on how to change the default AIX memory allocation setting, see Checking for malloc heap contention when running IBM DB2 on (AIX).