how to determine the value of max_async_ports

[zhj_1]

the type of box is superdome,database is oracle 8.1.7.4,DB have 1500 concurrent connections.

[G. Vrijhoeven]

Hi,

kmtune -l -q max_async_ports

HTH,

Gideon

[Stefan Farrelly]

/usr/sbin/kmtune|grep -i max_async_ports

[Naveej.K.A]

sam
kernel configuration
configurable parameters
max_async_ports

or from the command line
kmtune |grep max_async_ports

regds
naveej

[zhj_1]

sorry,i know how to modify the value,but i don't know the value should be modify to which value

[Hoefnix]

Hi,

checked some systems running multiple oracle databases (7.3.4 - 9.x) and all have it set to 50.

I don't know how to calculated but default is 50

HTH,
Peter

[Hoefnix]

Hi again,

From the OTN site(doc for version 9):

Kernel parameter settings Async driver Since the database was stored on raw devices, it is strongly advised to install the Async IO driver (/dev/async) and set the configurable kernel parameter max_async_ports to the maximum number of asyncdsk ports that can be open at one time, i.e. max_async_ports limits the maximum number of processes that can concurrently use /dev/async. As a guideline, set this parameter to the sum of processes from init.ora + number of background processes. The background processes started at instance startup will open /dev/async twice. If max_async_ports is reached, subsequent processes will use synchronous I/O [9].

I don't now if you store it on raw devices, but the rule how to calculate can help i hope.

http://otn.oracle.com/products/database/clustering/pdf/11iRACBM2.pdf

HTH,
Peter