topic Re: Kernel Parameters in Operating System - Linux

Kernel Parameters

varian_1 — Thu, 26 May 2005 04:45:20 GMT

Hi,

To increase MAX Network Connection and Max Shared Memory whcih kernel parameter in in RedHat Linux AS3 has to be changed. Also let us know the max range for this parameters.

Thnaks in advance.

Regards
Walter Crasto

Re: Kernel Parameters

Stuart Browne — Thu, 26 May 2005 05:04:11 GMT

The memory tuning is well documented on the Oracle site, as it's a huge user of it.

Basically, you'll want to look at the values of the '/proc/sys/vm' and '/proc/sys/kernel' structures.

To find out what the max values of these are depends on what kernel you are running, but make sure you have the 'kernel-doc' package installed, and read through '/usr/share/doc/kernel-doc-*/filesystems/proc.txt'.

Now, as for max network connections.. This sould be under '/proc/sys/net/ipv4/' somewhere if there were such a thing, but I've not heard of such a tunable varaible. By the same token, I've had linux boxes with many thousands of simultaneous connections without batting an eye-lid.

What sort of load were you planning on putting this machine through?

Re: Kernel Parameters

varian_1 — Thu, 26 May 2005 06:16:08 GMT

Hi,

Thanks for reply.

I have made the changes as per Oracle 9i requirements. Here I am using this server in test environment. Wants to set these parameters at max. possible value. My kernel version is " 2.4.21-4.ELsmp"

Regards

Varian

Re: Kernel Parameters

Steven E. Protter — Thu, 26 May 2005 07:32:39 GMT

You probably want to set the values not to the maximum, which can cause other system problems. You would be better as far as oracle is concerned to set the values a percentage above the minimum that oracle requires.

I take that value and add 50% where practical.

You change certain kernel parameters by merely echoing the new value to the parameter listed in the directories Stuart provided.

SEP

Re: Kernel Parameters

Steven E. Protter — Thu, 26 May 2005 08:51:36 GMT

Okay, set the value for shared memory to the total physical memory on the machine.

If you start having performance issues, don't say you weren't warned.

On HP-UX when Oracle's installer demanded we do the same thing, the system simply ignored the higher setting. I'm not sure what Linux will do in this case. Monitor system performance after making the changes.

SEP

Re: Kernel Parameters

Rick Beldin — Fri, 27 May 2005 14:55:56 GMT

If that is a RH kernel, it is very old. There are some serious performance, memory management and corruption issues which tend to be exposed on machines running Oracle.

I would upgrade to the U5 kernel, 2.4.21-32.0.1