IBM Power System POWER7 Series, Optimization And Tuning Manual

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POWER7 and Optimization and Tuning Guide
– In the stand-alone usage of ASM, unlike RAC, hdisks and hdiskpower devices do not
need to have Small Computer System Interface (SCSI) reservation disabled.
– The following initialization parameters must be adjusted for ASM:
• Add 16 to the value of processes.
• Add an additional 600 KB to the value of large pool size.
• Add to shared pool size the aggregate of the values that are returned by
these queries:
• SELECT SUM(bytes)/(1024*1024*1024) FROM V$DATAFILE;
• SELECT SUM(bytes)/(1024*1024*1024) FROM V$LOGFILE a, V$LOG b WHERE
a.group#=b.group#;
• SELECT SUM(bytes)/(1024*1024*1024) FROM V$TEMPFILE WHERE
status=’ONLINE’;
– For disk groups using external redundancy, every 100 GB of space needs 1 MB of
extra shared pool, plus 2 MB.
– For disk groups using normal redundancy, every 50 GB of space needs 1 MB of extra
shared pool, plus 4 MB.
– For disk groups using high redundancy, every 33 GB of space needs 1 MB of extra
shared pool, plus 6 MB.
For more information, go to:
http://docs.oracle.com/cd/E18283_01/server.112/e16102/asminst.htm#CHDBBIBF
Network
This section outlines the minimum values that are applicable to network configurations.
Kernel configurations
The following values can be considered as starting points for Oracle:
򐂰 Set sb_max >= 1MB (1048576), which must be greater than the maximum tpc or udp send
or recvspace (if you are using RAC and an especially large udp_recvspace , you might
need to increase sb_max ).
򐂰 Set tcp_sendspace = 262144 .
򐂰
Set
tcp_recvspace = 262144
.
򐂰 Set udp_sendspace = db_block_size * db_file_multiblock_read_count .
򐂰
Set
udp_recvspace= 10 * (udp_sendspace)
.
򐂰 Set rfc1323 = 1 .
򐂰 Ephemerals (non-defaults suggested for many connecting hosts or a high degree of
parallel query; also to avoid install-time warnings) should be set as follows:
– tcp_ephemeral_low=9000
– tcp_ephemeral_high=65500
– udp_ephemeral_low=9000
– udp_ephemeral_high=65500
Jumbo frames are Ethernet frames larger than the standard MTU size of 1500 bytes. They
can be up to 9000 bytes. They are used to reduce the number of frames to transmit a volume
of network traffic, but they work only if enabled on every
hop
in the network infrastructure.
Jumbo frames help reduce network and CPU processing impacts.