max_async_ports and aio_max_ops

[Carlos Roberto Schimidt]

HI,

The kernel parameter max_async_ports limits the maximum number of processes that can concurrently
use /dev/async. 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.

# kctune -d max_async_ports
Tunable Value Expression
Description
max_async_ports 50 Default
Maximum number of open asyncdsk ports

I have many oracle process using /dev/async

# fuser -u /dev/async 2>/dev/null | wc -w
103

Another kernel parameter is aio_max_ops and I read is possible monitor by glance, by I cant.

is not possible query the usage from these kernel resources using kcusage.

Who knows about get this information using adb or other tool?

I´d appreciate any help.

Tks

Schimidt

[RAC_1]

max_async_ports is for /dev/async, and other is for posix asynchrous operations. If you large number of oracle processes, increase max_async_ports.

Unless, you are 11.23, you can not monitor real time usage of max_async_ports. HP has some utility for that, conatct them, if you have support contract. On 11.23, you should be able to set kc usage alarm for it.

[RAC_1]

Refer following doc for explaination on these parameters.

http://www1.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000072678581

[Carlos Roberto Schimidt]

Hi,

I have HP-UX 11.23 but max_aysnc_ports is not possible monitor real time utilization:

# kcusage -d max_async_ports
Unsupported Tunable: max_async_ports

Support Team from HP are trying developer a program for get this information.

I made this question here if have anybody who knows how to do.

Tks

Schimidt