Vijay Adik vadik@us - IBM
Vijay Adik vadik@us - IBM
Vijay Adik vadik@us - IBM
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<strong>IBM</strong> Advanced Technical Support - Americas<br />
GPFS I/O Related Tunables<br />
� Refer Metalink note 302806.1<br />
Async I/O:<br />
� Oracle parameter filesystemio_options is ignored<br />
� Set Oracle parameter disk_asynch_io=TRUE<br />
� Prefetchthreads= exactly what the name says<br />
– Usually set prefetchthreads=64 (the default)<br />
� Worker1threads = GPFS asynch I/O<br />
– Set worker1threads=550-prefetchthreads<br />
� Set aio maxservers=(worker1threads/#cpus) + 10<br />
Other settings:<br />
� GPFS block size is configurable; most will use 512KB-1MB<br />
� Pagepool – GPFS fs buffer cache, not used for RAC but may be for<br />
binaries. Default=64M<br />
mmchconfig pagepool=100M<br />
© 2009 <strong>IBM</strong> Corporation<br />
April 17, 2009
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