SAP on HP-UX Best Practices - Part 2
Link back to: SAP on HP-UX Best Practices - Contents Last update: 14th April 2011
- Configuring HP-UX for SAP Applications
Configuring HP-UX for SAP Applications
HP-UX OS Patches
For general HP-UX Patch Management documentation see: http://www.hp.com/go/patchmgmt-docs
The minimum HP-UX OS patch recommendations for SAP can be found in the following places:
For SAP ABAP Kernel see:
- SAP Note 837670
For SAP liveCache/MaxDB see:
- SAP Note 916646 - liveCache/MaxDB Version 7.5 to 7.8 (IA64/Itanium)
- SAP Note 916644 - liveCache/MaxDB Version 7.5 to 7.8 (PA-RISC)
- SAP Note 752582 - liveCache/MaxDB Version 7.4 (IA64/Itanium)
For SAPJVM see:
- SAP Note 1367498 "SAP JVM installation prerequisites"
For HP JVM recommendations from HP see:
Where to get HP-UX Patches:
Recommended HP-UX Kernel Tunables/Parameters
Refer to SAP Note 172747 (which is most up to date and covers all current HP-UX Versions)
Older versions of HP-UX kernel parameter recommendations may also be found in the SAP Install Guides, see http://service.sap.com/instguides
For some SAP DB/MaxDB specifics please see SAP Note 628131
For Java specific information see SAP Note 534867
Be aware of percentage based and/or dynamic HP-UX kernel tunables/parameters:
- 5% of memory can quickly become a lot. (Be careful with buffercache/filecache settings)
- Some HP-UX kernel parameters are dynamic and can also rapidly grow (Be careful of vx_ninode and vxfs_bc_bufhwm)
- Ask your HP support representative for advice.
See SAP Note 1112627 for a detailed explanation of swap sizing and pseudo-swap
In general device swap configurations of 1.5x or 2x RAM have proven appropriate for the majority of SAP installations. The recommendation is to set device swap to 2x RAM (minimum 20GB).
Refer to SAP Note 153641 for a detailed explanation of swap requirements on a per SAP instance basis.
Note: the 20GB recommendation is only a minimum.
Mount options and I/O Types
- See SAP Note 1077887 for details on how to configure "buffered I/O", "direct I/O" (DIO) and "concurrent I/O" (CIO)
- SAP Note 793113 contains a good overview of the main I/O topics in an Oracle context.
- SAP Note 993848 covers the mount options topic for MaxDB/LiveCache.
Blocksize recommendations (for database filesystems)
- Refer to the section "Setting the correct blocksizes" of SAP Note 1077887
Note: "DB2 LUW (Linux Unix Windows)" is known at SAP as "DB6"
Recommended database parameter settings:
- DB2 ver. 8 - see SAP Note 584952
- DB2 ver. 9.1 - see SAP Note 899322
- DB2 ver. 9.5 - see SAP Note 1086130
- DB2 ver. 9.7 - see SAP Note 1329179
- MaxDB - see SAP Note 1139904
- Oracle <=9i - see SAP Note 124361
- Oracle 10.2.0.2 - see SAP Note 830576
- Oracle 10.2.0.4 - see SAP Note 830576
- Oracle 11.2.0 - see SAP Note 1431798
For further information on DB2 configurations see:
For further information on MaxDB configurations see:
For further information on Oracle configurations see:
Depending on SAP Kernel version either the Platform HP JDK will be used, or the SAPJVM.
- HP JVM (Platform JDK)
- For information on the SAP supported Platform JDK for HP-UX see SAP Note 716926 (which also includes the JDK parameters necessary for SAP)
- If you need to use multiple JDK minor versions (e.g. 1.4.11 and 1.4.12) on the same HP-UX host please take care when doing so, since the default paths (e.g. /opt/java1.4 in this case) are the same. Please contact support for advice on how to do this.
- See SAP Note 1396516 for information on SAP JVM Performance tips on HP-UX.
Java VM OS Patch prerequisites on HP-UX
- See the above section on HP-UX OS Patches
Recommended Java VM (JVM) settings
- HP JVM (Platform JDK)
- See SAP Note 723909 (which covers all platforms)
- Note: When setting the heap size of SAP Java node(s), please consider that there needs to be enough physical memory to accommodate all the SAP Java nodes plus space for OS and other processes (e.g. database, ABAP Kernel etc.).
- SAPJVM settings are predefined in the configuration templates of the relevant SAP product
See SAP Note 918279 for the current version of the saposcol for HP-UX
Correct sizing is essential for SAP Systems to perform as desired.
For existing SAP Systems it is possible to measure current system utilization, e.g. with HP Capacity Advisor Consolidation software http://www.hp.com/go/capad
HP specific Sizing is available from: "Sizing for SAP"
For further information on SAP sizing see:
- SAP Sizing Guide - Theory and Practice of Sizing SAP Software
- Sizing SAP Solutions https://service.sap.com/sizing
- SAP Quick Sizer https://service.sap.com/quicksizer
- SAP Standard Application Benchmarks - Published Results http://www.sap.com/benchmark
- Right-Sizing Your Hardware
- Performance Analysis and Measurements - Sizing
- System Sizing Guidelines for Integrity Virtual Machines Deployment
The exact sizing of memory depends to a great extent on the application and system workload, however some general hints:
- Base RAM sizing on System power (e.g. SAPS) and not number of CPUs/cores. The more powerful the server is, the more users/applications you will (potentially) have and that all requires more memory.
- PA-RISC and Itanium (aka. IA64, Integrity) have approx. the same memory usage for the same application in the same version. Although Itanium executables/libraries are larger, they are shared and do not constitute a significant memory overhead compared to the rest of the SAP system (e.g. shared memory)
- If upgrading application consider what impact this will have. Newer SAP Versions require more memory than previous versions; Unicode systems also require more memory than non-unicode.
Memory Usage (What is Using all of the Memory?)
If your system is consuming more memory than you think it should, then try checking the following:
- SAP Instance Memory configurations (especially shared memory segments and Java configurations)
- Database Memory configuration
- Configuration of HP-UX Kernel Parameters, see SAP Note 172747
- SAP Note 1112627 "SAP on HP-UX: Recommendations for swap and pseudo swap"
- Check the following document which explains many aspects of HP-UX memory usage and how to identify memory users: "HP-UX Memory Usage - What is using all of the memory"
- Check the following HP white paper for a technical explanation of HP-UX Memory concepts: "HP-UX Memory Management White Paper"
- HP White Paper: The HP-UX 11i v3 Memory Management Subsystem
In general, the use of Hyperthreading should improve performance for most SAP workloads. However there may be workload scenarios which benefit less from Hyperthreading.
See the following for further details:
- SAP Note 1329360 "Using Itanium Hyperthreading on HP-UX"
- HP Knowledge-on-Demand: Montecito Hyper-Threading on HP-UX 11i v3
- Dynamic logical processors for Hyper-Threading on HP-UX 11i v3
These are some general tips which apply to typical customer scenarios. Since there will also be exceptions to the rule please be sure to test & verify the effects of changes in test environments before releasing to production.
- Check filesystem blocksizes and mount options (SAP Note 1077887 "SAP on HP-UX: mount & filesystem options for best performance")
- If inode contention is being experienced, consider using "concurrent I/O" (SAP Note 1077887 "SAP on HP-UX: mount & filesystem options for best performance")
- HP White Paper Performance improvements using Concurrent I/O on HP-UX 11i v3 with OnlineJFS 5.0.1 and the HP-UX 11i Logical Volume Manager
- HP White Paper HP-UX VxFS tuning and performance
- If your alert log reports "log file switch (checkpoint incomplete)", then configuring multiple DB Writer processes (DBWR), and possibly shadow log writer processes (LGWR), could improve performance.
- HP White Paper HP-UX VxFS mount options for Oracle Database environments
- Performance Analysis and Measurements - Achieving Optimal Performance for SAP Solutions
- Performance of SAP Software Solutions https://service.sap.com/performance
For optimal LiveCache performance use HP-UX 11.31, see the following for details:
- SAP Note 1357553 "MaxDB / liveCache Performance on HP-UX"
- A comprehensive analysis of SAP liveCache testing by SAP and HP
- Common Misconfigured HP-UX Resources
- HP-UX Performance Cookbook
- Knowledge-on-Demand Webcast: HP-UX 11i v3 performance & scalability
Troubleshooting Tools and Tips:
- Knowledge-on-Demand Webcast: HP-UX 11i v3 performance trouble-shooting â€“ Tools and tips
- Knowledge-on-Demand Webcast: Glance and system performance optimization
Making the most of NUMA
The majority of HP-UX Servers are based on the NUMA (Non Uniform Memory Access) architecture. Depending on how the HP-UX Server has been partitioned and the type of workload, it may be advantageous to make use of NUMA optimizations.
See the NUMA/HP-UX sources below for further information:
SAP on HP-UX
- HP Knowledge-on-Demand: SAP on HP-UX 11i v3
- Using HP-UX features to enhance the performance and scalability of an HP Integrity Superdome SD64B server running SAP
- HP Knowledge-on-Demand: HP-UX 11i v3 LORA - Locality-optimized Resource Alignment
- HP White Paper: Locality-Optimized Resource Alignment
- HP-UX Processor Sets - A Technical White Paper
- SAP Note 1225732 Oracle 10.2 ccNUMA optimization on HP-UX"
- SAP Note 1506703 Oracle 11.2 ccNUMA optimization on HP-UX"
- HP White Paper: The Oracle Database on HP Integrity servers
- HP White Paper: Considerations when running Oracle Database 10g or 11g in a ccNUMA environment under HP-UX
- HP White Paper: Dynamic server resource allocation with Oracle Database 10g or 11g on an HP-UX ccNUMA-based server