Installation prerequisites for Db2 pureScale feature (AIX)

Before you install a Db2 pureScale environment for the first time, ensure that you have your Db2 pureScale installation plan created. Your installation plan helps ensure that your system meets the prerequisites and that pre-installation tasks are done.

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.

This topic details the requirements for: software prerequisites (including operating system, OpenSSH, IBM Spectrum® Scale, and Tivoli SA MP), storage hardware, and hardware and firmware (network adapters, cables, switches).

Software prerequisites

Table 1. Software prerequisites - AIX operating system version and technology levels
AIX version Technology level Minimum Service Pack (SP) level AIX Known Issue
AIX 7.1 3 5 IV72952
AIX 7.1 4 1  
AIX 7.1 5 3 IJ07998 IJ13283
AIX 7.2 0 1  
AIX 7.2 1 1  
AIX 7.2 2 1  
AIX 7.2 3 1  
AIX 7.2 4 1 IJ11241 IJ11146 IJ11326 IJ15063
AIX 7.3 2 1  
AIX 7.3 3 1  
Note:
  • RoCE networks require RDMA Verbs. The fileset level required for RDMA Verbs is included in the AIX image and is called ofed.core.rte.
  • If the AIX system is running on a Technology Level with the minimum Service pack that is specified in the table, all Known Issues listed in the row must be installed. For a system that runs on a Technology Level with a later Service Pack, verify whether the Known Issue fix is included in the Service Pack level. To obtain fixes for the Known Issues for a system that is running a Service Pack higher than the minimum required and lower than the Service Pack the fix was first included in, see IBM Support Fix Central.
  • When POWER11 systems are used with Db2 version 11.5, users must have AIX 7.2 TL05 SP9 or higher SP, or AIX 7.3 TL02 SP4 or higher SP, based on what is listed [Table 1]. Db2 v11.5.9.0 with cumulative special build 63280 or higher must be used as the Db2 version on POWER11.
  • The AIX level must be AIX 7.2 TL05 SP9 or higher SP when EC85 or EC86 cards are used.
  • The AIX level must be AIX 7.3 TL02 SP4 or higher SP when EC71 or EC72 cards are used.
The following list includes the required software:
Note:
  • IBM Storage Scale and Tivoli SA MP:
    • The required level of IBM Tivoli System Automation for Multiplatforms (Tivoli SA MP) and IBM Storage Scale, along with any necessary fix for a particular Db2 release and fix pack, must be obtained in the db2 images for the particular release and fix pack. They must be obtained, installed, and updated through the standard Db2 installation and upgrade procedures. Do not download and install individual fixes manually without any guidance from a Db2 service.
  • RSCT:
    • The IBM Reliable Scalable Cluster Technology (RSCT) peer domain (RSCT:) level that is included within a Tivoli SA MP package is always the 'minimum' supported level.
  • AIX:
    • Workload partitions (WPARs) are not supported in a Db2 pureScale® environment.
Note: Secure Copy Protocol (SCP) is used to copy files between cluster caching facilities and members

Supported RoCE Cards

On an RDMA protocol network, the Db2 pureScale environment is supported on a POWER11-compatible rack-mounted server that supports one of the following Ethernet RoCE adapters:
  • PCIe5 2-port 200/100 GbE RoCE Adapter x16 adapter with feature code EC85, EC86
  • PCIe4 2-port 10 GbE RoCE SFP28 Adapter x8 adapter with feature code EC71, EC72
  • PCIe4 4-port 25/10/1 GbE RoCE SFP28 Adapter x16 adapter with feature code EN24, EN26 ( using 2 ports )

Storage hardware requirements

Db2 pureScale Feature supports all storage area network (SAN) and directly attached shared block storage, however for more information about Db2 cluster services support, see the “Shared storage support for Db2 pureScale environments” topic. The following storage hardware requirements must be met for Db2 pureScale Feature support.
Table 2. Minimum and recommended free disk space per host
  Recommended free disk space Minimum required free disk space
Disk to extract installation 3 GB 3 GB
Installation path 6 GB 6 GB
/tmp directory 5 GB 2 GB
/var directory 5 GB 2 GB
/usr directory 2 GB 512 MB
Instance home directory 5 GB 1.5 GB1
root home directory 6 GB 5 GB
Note: 1 The disk space that is required for the instance home directory is calculated at run time and varies. Approximately 1 to 1.5 GB is normally required.

The following shared disk space must be free for each file system:
  • Instance shared directory: 10 GB1
  • Data: dependent on your specific application needs
  • Logs: dependent on the expectant number of transactions and the applications logging requirements

A fourth shared disk is required to configure as the Db2 cluster services tiebreaker disk.

Hardware and firmware prerequisites

Note: Given the widely varying nature of such systems, IBM cannot practically guarantee to have tested on all possible systems or variations of systems. If problem reports for which IBM deems reproduction necessary, IBM reserves the right to attempt problem reproduction on a system that might not match the system on which the problem was reported.

On a TCP/IP over Ethernet (TCP/IP) protocol network, a Db2 pureScale environment is supported on any POWER9 or POWER10 rack-mounted server.

On an RDMA protocol network, the Db2 pureScale environment is supported on a POWER11-compatible rack-mounted server that supports one of the following Ethernet RoCE adapters:
  • PCIe4 4-port 25/10/1 GbE RoCE SFP28 Adapter x16 adapter with feature code EN24, EN26 (using 2 ports)
On an RDMA protocol network, the Db2 pureScale environment is supported on POWER9-compatible rack-mounted server, which supports one of the Ethernet RoCE adapters in the following list:
  • PCIe3 2-port 10 Gb NIC & RoCE SR/Cu adapter with feature code EC2S, EC2R
  • PCIe3 2-port 100 GbE (NIC and RoCE) QSFP28 adapter with feature code EC3L, EC3M
  • PCIe4 2-port 100 GbE RoCE x16 adapter with feature code EC66, EC67

On a TCP/IP protocol over Ethernet (TCP/IP) network, a Db2 pureScale environment requires only one high-speed network for the Db2 cluster interconnect. Running your Db2 pureScale environment on a TCP/IP network can provide a faster setup for testing the technology. However, for the most demanding write-intensive data sharing workloads, an RDMA protocol over Converged Ethernet (RoCE) network can offer better performance.

RoCE networks that use RDMA protocol require two networks: one (public) Ethernet network and one (private) high-speed communication network for communication between members and CFs. The high-speed communication network must be an InfiniBand network, a RoCE network, or a TCP/IP network. A mixture of these high-speed communication networks is not supported.

Note: Although a single Ethernet adapter is required on a host for the public network in a Db2 pureScale environment, set up Ethernet bonding for the network if you have two Ethernet adapters. Ethernet bonding (also known as channel bonding) is a setup where two or more network interfaces are combined. Ethernet bonding provides redundancy and better resilience if Ethernet network failures. Refer to your Ethernet documentation for instructions on configuring Ethernet bonding. Network interfaces that are used for a Db2 pureScale cluster interconnect with RDMA must not be bonded.

It is also a requirement to keep the maximum transmission unit (MTU) size of the network interfaces at the default value of 1500 for both TCP and RDMA network types. For more information on configuring the MTU size on AIX, see Change MTU of Host Ethernet Adapter.

The rest of this hardware and firmware prerequisites section applies to using RDMA protocol.

Cables and switches: a Db2 pureScale environment is supported on any Ethernet adapter (10GbE or other supported speed) and switch that is supported by a POWER9 or POWER10 server.

The communication adapter port can be:
  • a RoCE network.
To use a RoCE network, all network adapters and switches must have remote direct memory access (RDMA) over Converged Ethernet (RoCE).
The hardware and firmware requirements for IBM validated servers are listed in these tables later in this section:
Server-specific hardware details:

Servers in a Db2 pureScale environment must use both an Ethernet network and high-speed communication adapter port.

Note:
  • RoCE adapters do not support virtualization. Each LPAR requires a dedicated RoCE adapter. For example, if a machine has two LPARs (one for CF and one for member), each of these LPARs must have its own dedicated RoCE adapter.
  • For production clusters, it is strongly recommended that each Db2 member and each CF be deployed into their own LPAR. The CF should have a dedicated CPU to provide the low-latency responses required for communication with the Db2 members. Db2 members will also benefit from dedicated CPUs for best-in-class performance.
Note:
  • When you acquire systems, consider the I/O ports available and future workloads for greater flexibility and scalability. For more information about selecting the hardware, see Site and hardware planning in the IBM System Hardware documentation.

Cable Information:

Table 3. 10GE cable information (1, 3 and 5 meters)
  1 meter 3 m 5 m
Feature Code number EN01 EN02 EN03
Note:
  • IBM Qualified Copper SFP+ cables or standard 10-Gb SR optical cabling (up to 300 m cable length) can be used for connecting RoCE adapters to the 10GE switches.
Table 4. IBM Qualified QSFP+ Cable Information as ISLs for 10GE RoCE connections
  1 meter 3 m
Feature Code number EB2B EB2H
Note:
  • IBM Qualified QSFP+ cables can be used as inter-switch links between 10GE switches.

For a list of 100GE cables that are compatible with your adapter, see the IBM Power9 documentation. For example, the cables available for the EC3L/EC3M adapter on POWER9 are listed under the adapter here.

Switches:
For the configuration and the features that are required to be enabled and disabled, see Switch configuration on an RoCE network (AIX).
Table 5. IBM validated 10GE switches for RDMA
IBM Validated Switch
Lenovo RackSwitch G8124
Lenovo RackSwitch G8264
Juniper Networks QFX3500 Switch
Lenovo RackSwitch G8272
Cisco Nexus C93240YC-FX2
Table 6. IBM validated 100GE switches for RDMA
IBM Validated Switch
Cisco Nexus C9336C-FX2
Cisco Nexus C93240YC-FX2
Note:
  • IBM Qualified Copper SFP+ cables or standard 10-Gb SR optical cabling (up to 300 m cable length) can be used as inter-switch links. Cables that are 3 m or 7 m SFP+ cables that are supplied by Juniper can be used between Juniper switches.
  • For the configuration and the features that are required to be enabled and disabled, see Switch configuration on an RoCE network (AIX). Any Ethernet switch that supports the listed configuration and features is supported. The exact setup instructions might differ from what is documented in the switch section, which is based on the IBM validated switches. Refer to the switch user manual for details.
You must not intermix 10-Gigabit, 40-Gigabit, and 100-Gigabit Ethernet network switch types. The same type of switch, adapter, and cables must be used in a cluster. A server that uses a 10G adapter must use a 10G type switch and the corresponding cables. A server that uses a 40G adapter must use a 40G type switch and the corresponding cables. A server that uses a 100G adapter must use a 100G type switch and the corresponding cables.

If you are using two switches in the Db2 pureScale environment, two or more inter-switch links (ISL) are required. To help with performance and fault tolerance to inter-switch link failures, use half the number of inter-switch link cables as there are total communication adapter ports that are connected from CFs and members to the switches. For example, in a two switch Db2 pureScale environment where the primary and secondary CF each has four cluster interconnect netname(s), and there are four members, use six inter-switch links (6 = (2 x 4 + 4) /2).

1 For better I/O performance, create a separate IBM Storage Scale file system to hold your database and specify this shared disk on the create database command.