How to setup Redhat 6.0 semaphore kernel variable for INFORMIX?
A user asked how to change kernel parameters like SHMMAX, SHMMIN and semaphore limits for Informix IDS on Red Hat 6.0, since they weren't exposed in the kernel config menus. Replies said no tuning was actually needed for modest configurations — several ran IDS on RH6.0 unchanged — and pointed out SHMMAX is shared memory, not semaphores. Practical answers: grep the headers under /usr/src/linux for the symbols and rebuild, or, on 2.2 kernels, set values at runtime via /proc/sys/kernel/shmmax (see Documentation/sysctl/kernel.txt).
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Hi all, Informix required to tune semaphore kernel variable for running Informix engine. I don't know where I can set the new value of semaphore to run IDS on Redhat 6.0 as SHMMAX, SHMMIN, SHMMNI or.... I don't find them in make xmenuconfig.... Thanks in advance.
In article <HuBv3.70460$jl.44881274@newscontent-01.sprint.ca>, Huy Vu <huyv@usa.net> wrote: >Informix required to tune semaphore kernel variable for running Informix >engine. I don't know where I can set the new value of semaphore to run IDS >on Redhat 6.0 as SHMMAX, SHMMIN, SHMMNI or.... Unless you're trying to run some godawful-large configuration, you won't need to tune the Red Hat 6.0 kernel to run OnLine 7.30.UC7...
Huy Vu wrote: > Informix required to tune semaphore kernel variable for running > Informix engine. I don't know where I can set the new value of > semaphore to run IDS on Redhat 6.0 as SHMMAX, SHMMIN, SHMMNI or.... > > I don't find them in make xmenuconfig.... I didn't do any tuning of my RH6.0 kernel and IDS runs OK. Are you sure you need to alter something? How many users are you planning to have? Each user requires a semaphore, and there are a few strays required too (my knowledge is rusty; it applies strictly to 5.x, and may be slightly off for more recent versions). Also, SHMMAX is for shared memory; SEMMAX would be related to semaphores. But I did not have to reconfigure either with RH6.0. -- Jonathan Leffler (jleffler@informix.com, jleffler@earthlink.net) Guardian of DBD::Informix v0.60 -- see http://www.perl.com/CPAN #include <disclaimer.h>
But where can I setup these kernel variable under RedHat 6.0? I don't know where can I change the value for them... H.V Jonathan Leffler <jleffler@earthlink.net> wrote in message news:37C836E3.29D1@earthlink.net... > Huy Vu wrote: > > Informix required to tune semaphore kernel variable for running > > Informix engine. I don't know where I can set the new value of > > semaphore to run IDS on Redhat 6.0 as SHMMAX, SHMMIN, SHMMNI or.... > > > > I don't find them in make xmenuconfig.... > > I didn't do any tuning of my RH6.0 kernel and IDS runs OK. > > Are you sure you need to alter something? How many users are you > planning to have? Each user requires a semaphore, and there are > a few strays required too (my knowledge is rusty; it applies strictly > to 5.x, and may be slightly off for more recent versions). Also, > SHMMAX is for shared memory; SEMMAX would be related to semaphores. > But I did not have to reconfigure either with RH6.0. > > -- > Jonathan Leffler (jleffler@informix.com, jleffler@earthlink.net) > Guardian of DBD::Informix v0.60 -- see http://www.perl.com/CPAN > #include <disclaimer.h> >
Huy Vu wrote: > But where can I setup these kernel variable under RedHat 6.0? > I don't know where can I change the value for them... Nor do I. I suspect you'd do better in a Linux kernel related news group, though. > Jonathan Leffler <jleffler@earthlink.net> wrote: > > Huy Vu wrote: > > > Informix required to tune semaphore kernel variable for running > > > Informix engine. I don't know where I can set the new value of > > > semaphore to run IDS on Redhat 6.0 as SHMMAX, SHMMIN, SHMMNI... > > > > > > I don't find them in make xmenuconfig.... > > > > I didn't do any tuning of my RH6.0 kernel and IDS runs OK. > > [...] -- Jonathan Leffler (jleffler@informix.com, jleffler@earthlink.net) Guardian of DBD::Informix v0.60 -- see http://www.perl.com/CPAN #include <disclaimer.h>
To locate the symbols do a find . -name "*.h" | xargs grep string_2_find Example: cd /usr/src/linux find . -name "*.h" | xargs grep SHMMIN Huy Vu (huyv@usa.net) wrote: : Hi all, : Informix required to tune semaphore kernel variable for running Informix : engine. I don't know where I can set the new value of semaphore to run IDS : on Redhat 6.0 as SHMMAX, SHMMIN, SHMMNI or.... : I don't find them in make xmenuconfig.... : Thanks in advance. -- While Alcatel may claim ownership of all my ideas (on or off the job), Alcatel does not claim any responsibility for them. Warranty expired when u opened this article and I will not be responsible for its contents or use.
In article <Az2y3.77759$jl.50292606@newscontent-01.sprint.ca>,
Huy Vu <huyv@usa.net> wrote:
>But where can I setup these kernel variable under RedHat 6.0?
>I don't know where can I change the value for them...
In the 2.2 kernel, you can set shmmax dynamically.
# cat /proc/sys/kernel/shmmax
33554432
shows you the current value (32MB, here).
# echo 1073741824 > /proc/sys/kernel/shmmax
sets a new value (1GB here).
See Documentation/sysctl/kernel.txt for details (a subdirectory of the
Linux source distribution which usually lives in /usr/src/linux if
you've installed the source).
--Malcolm
--
Malcolm Beattie <mbeattie@sable.ox.ac.uk>
Oxford University Computing Services
"I permitted that as a demonstration of futility" --Grey Roger