Fwd: Re: Shared memory for RH Linux 7.1

Started by Ryan Mahoneyover 24 years ago4 messages
#1Ryan Mahoney
ryan@paymentalliance.net
Show quoted text

This is true. You can adjust the value in the /proc/sys/kernel/shmmax
file. If you change the value it will be reset when you reboot, so you
will need to write a start-up script to always change this value if you
want it to be permanent.

-r

At 09:51 AM 5/24/01 -0700, you wrote:

In the past, I had to change the RedHat Linux kernel so that the
shared memory was set to something much higher than the default (which
I think was about 32 MBytes). It seems that this is no longer
necessary in RH 7.1 (kernel 2.4). Can someone confirm this?

-Tony

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#2Ryan Mahoney
ryan@paymentalliance.net
In reply to: Ryan Mahoney (#1)
Re: Re: Shared memory for RH Linux 7.1

This value can be dynamically changed by:

echo "new value here" > /proc/sys/kernel/shmmax

Glad I bought that expensive RedHat support contract!

-r

At 08:02 PM 5/24/01 +0200, Poul L. Christiansen wrote:

Show quoted text

I think you still need to set your shared memory size, because my Redhat
7.1 gives me this:

[root@localhost kernel]# cat /proc/sys/kernel/shmmax
33554432
[root@localhost kernel]# uname -a
Linux localhost.localdomain 2.4.2-2 #1 Sun Apr 8 20:41:30 EDT 2001 i686
unknown

I think shared memory is set this low for compatability reasons, but I'm
not sure.

Poul L. Christiansen

Tony Reina wrote:

In the past, I had to change the RedHat Linux kernel so that the
shared memory was set to something much higher than the default (which
I think was about 32 MBytes). It seems that this is no longer
necessary in RH 7.1 (kernel 2.4). Can someone confirm this?

-Tony

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#3Matthew Kirkwood
matthew@hairy.beasts.org
In reply to: Ryan Mahoney (#2)
Re: Re: Shared memory for RH Linux 7.1

On Thu, 24 May 2001, Ryan Mahoney wrote:

echo "new value here" > /proc/sys/kernel/shmmax

The new canonical way is to:

$ sysctl -w kernel.shmmax="new value"

you can arrange for it you happen at boot time via /etc/sysctl.conf.

Matthew.

#4Michael J Schout
mschout@gkg.net
In reply to: Ryan Mahoney (#1)
Re: Fwd: Re: Shared memory for RH Linux 7.1

On Thu, 24 May 2001, Ryan Mahoney wrote:

This is true. You can adjust the value in the /proc/sys/kernel/shmmax
file. If you change the value it will be reset when you reboot, so you
will need to write a start-up script to always change this value if you
want it to be permanent.

or you can let sysctl do it with this in /etc/sysctl.conf:

kernel.shmmax = 268435456

(obviously changing the value with what is appropriate for your machine).

This is for a RH 6.2 box. DOnt know if its the same on 7.1. We switched to
FreeBSD between redhat 6.2 and 7.0, so we dont have any RH7.1 boxes laying
around. I suspect it hasn't changed though.

Mike