IBM DB2 V8 사용자 설명서

7. Recommendations from the j oint IBM/SAP Platform Team:

Always use the latest z/VM release available , currently z/VM 5.3
Apply z/VM 5.1 APAR 63636 (PTF UM31312)
Apply all z/VM APARs listed in OSS Note 81737
Additional z/VM Considerations (these are specific to the customer configuration

and the workload characteristics) :

Consider HiperSockets , Vdisk, Vlan for network/swapping optimization
Consider workload distribution techniques such as add/reduce CPUs

dynamically as LPAR load changes and distribute workload over
day/night/weekend

Disable unused Linux guests to eliminate resource consumption (memory,

CPU)

Limit number of CPUs per Linux guest to reduce overhead cycles for

unused CPUs

Use FCP/SCSI devices instead of FICON/ECKD or ESCON to improve

throughput

Use Quick Dispatch for dialog intensive Linux guests to improve response

time

Review possible overcommitment of memory to avoid paging in z/VM

Apply the Fixed I/O Buffers Fix (SLES 9 SP1) available at

http://www.128.ibm.com/developerworks/linux/linux390/perf/tuning_rec_fixed_io_buffers.html

For additional fixes and tuning hints please see:

http://www.128.ibm.com/developerworks/linux/linux390/index.html

Use multiple swap volumes to avoid I/O bottlenecks.
Always use the latest available Linux kernel (currently SLES 10 SP1)
Configure swap volumes on the disk subsystem so that multiple channels are used.

If for example 15 of the 2.3 GB logical swap volumes are being mapped to a single
72 GB physical drive the throughput rate will be low.

FICON can support more swap volumes than channels. For example if you are

using 8 FICON channels then define 16-24 swap devices.

In Linux set the priority equal for all swap volumes.
Minimize paging and swapping.

Define the Linux guests as small as possible without

having Linux swapping occur on a regular basis.

If using extended memory for z/VM avoid paging in and out of extended memory.
Do not use z/VM TCP/IP as an IP router, this results in high CPU consumption.
Do not use MDC for SAP, this will conserve memory.
Tune the number of SAP work processes using SAP transaction SM50 or SM66.
For the HiperSocket definition to the DataBase LPAR use an MTU size of 16K or

larger.

IBM Solutions Technical Sales (STS) 12/18/2007Page 49 of 51

12/18/2007
Planning and Preparation Guide for SAP NetWeaver Version 6.40: z/OS Implementation