High shmmax value in Redhat 6.3

Posted by xpapad on Server Fault See other posts from Server Fault or by xpapad
Published on 2013-05-08T17:20:51Z Indexed on 2013/11/12 21:57 UTC
Read the original article Hit count: 204

Filed under:

redhat

|

postgresql

|

kernel

|

shmmax

We are using Redhat 6.3 with 30G RAM to host our Postgres server.

The (default) shmmax value is 68,719,476,736

In some forums I have read that having an shmmax value larger than the RAM causes extensive paging, but in the Redhat forums it warns against changing a kernel parameter that is already configured to a value larger than the minimum requirements for an environment.

In ServerFault I've read that this probably has no impact.

So is there any impact of having shmmax value > RAM in a DB server, or the kernel understands this and handles it appropriately?

Thanks

© Server Fault or respective owner

Related posts about redhat

Invalid configuration `noarch-redhat-linux-gnu': machine `noarch-redhat' not recognized

as seen on Server Fault - Search for 'Server Fault'
When I try to build rpm from src rpm (Apache 2.4.1) I got this error: rpmbuild -tb httpd-2.4.1.tar.bz2 --ba httpd.spec + ./configure --build=x86_64-redhat-linux-gnu --host=x86_64-redhat-linux-gnu --target=noarch-redhat-linux-gnu --program-prefix= --prefix=/usr --exec-prefix=/usr --bindir=/usr/bin… >>> More
`# probe: true` in /etc/rc.d/init.d/* files on a RedHat system

as seen on Server Fault - Search for 'Server Fault'
Some files (e.g. nfs, nfslock, bind) in my /etc/rc.d/init.d/ directory have in their comment header a line such as: # probe: true I found that those particular scripts has the probe verb i.e.: service nfs probe But this is due to the fact that the mentioned scripts has code that deals with the… >>> More
Redhat Software RAID 1 not syncing

as seen on Server Fault - Search for 'Server Fault'
Hey guys, I setup a software RAID 1 on a Redhat server, everything went sweet and it synced the first time. The other day the raid failedover for some reason and the disks hadn't been syncing since that first time, so it went back to 2 weeks ago when we did the first sync. We got the system back… >>> More
Failed to start X server. REDHAT LINUX 5.3

as seen on Super User - Search for 'Super User'
I installed Red-hat 5.3 problem is that it is not showing graphical interface. only kernel / command prompt is available. I tried startx, then I got this msg No video BIOS modes for chosen depth also showing that ERROR: Failed to start X server. What should I do? >>> More
Problems installing Memcache (PECL extension)

as seen on Server Fault - Search for 'Server Fault'
I have installed memcached fine, and now I will need to install PECL extension memcache. Im running RedHat x86_64 es5. The installation gives me this: downloading memcache-2.2.6.tgz ... Starting to download memcache-2.2.6.tgz (35,957 bytes) ..........done: 35,957 bytes 11 source files, building running:… >>> More

Related posts about postgresql

Postgresql fails to start on Ubuntu 10.04.4 LTS

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I installed postgresql 9.2 from add-apt-repository ppa:pitti/postgresql using apt-get install postgresql-9.2 At the end of the install and every time I try to launch postgresql by using the following command /etc/init.d/postgresql start or service postgresql start I get this error: Error:… >>> More
can't install psycopg2 in my env on mac os x lion

as seen on Server Fault - Search for 'Server Fault'
I tried install psycopg2 via pip in my virtual env, but got this error: ld: library not found for -lpq (full log here: http://pastebin.com/XdmGyJ4u ) I tried install postgres 9.1 from .dmg and via port, (gksks)iMac-Alexander:~ lorddaedra$ locate libpq /Developer/SDKs/MacOSX10.7.sdk/usr/include/libpq /Developer/SDKs/MacOSX10… >>> More
Postgresql has broken apt-get on Ubuntu

as seen on Super User - Search for 'Super User'
On ubuntu 12.04, whenever I try to install a package using apt-get I'm greeted by: The following packages have unmet dependencies: postgresql-9.1 : Depends: postgresql-client-9.1 but it is not going to be instal led E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a so lution)… >>> More
Installing PostgreSQL on FreeBSD (with ports)

as seen on Server Fault - Search for 'Server Fault'
Hey everyone, I am trying to install (using ports) PostgreSQL on a virtual server, running FreeBSD. My one question is this: Which of the following should I install? postgresql-contrib postgresql-docs postgresql-jdbc postgresql-libpgeasy postgresql-libpq++ postgresql-libpqxx postgresql-odbc … >>> More
Strange permission errors in new PostgreSQL installation

as seen on Server Fault - Search for 'Server Fault'
A freshly installed PostgreSQL (with configuration overwritten) won't start: $ sudo service postgresql start * Starting PostgreSQL 9.1 database server * Error: could not read /etc/postgresql/9.1/main/postgresql.conf: Permission denied Looks like it should be able to read it though: $ ls -l postgresql… >>> More