LinuxQuestions.org
View the Most Wanted LQ Wiki articles.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Distributions > Red Hat
User Name
Password
Red Hat This forum is for the discussion of Red Hat Linux.

Notices

Reply
 
Search this Thread
Old 12-19-2006, 08:18 AM   #1
czamora
Member
 
Registered: May 2006
Posts: 52

Rep: Reputation: 15
Centos 4 runs out of memory where Centos 3 didn't!


Hi,

I have been running a web server on the typical LAMP configuration for a long time. For the last months it was on Centos 3 and everything went ok. Then I upgraded to Centos 4, and suddenly the server runs out of memory every so often (alsmost once a day) and needs to be rebooted. The only thing I did was to upgrade to a "supposedly" improved distro version!

When the memory is low, and if it lets me run "ps -ef" what I see is dozens of httpd and sendmail processes (my web site does allow for users to send email messages among themselves).

Any hints on what may be causing this?

Thanks a lot.
 
Old 12-20-2006, 05:26 PM   #2
Brian1
Guru
 
Registered: Jan 2003
Location: Seymour, Indiana
Distribution: Distribution: RHEL 5 with Pieces of this and that. Kernel 2.6.23.1, KDE 3.5.8 and KDE 4.0 beta, Plu
Posts: 5,700

Rep: Reputation: 61
Have those two programs been updated during the centos upgrade. If so maybe check to see if there are updates for them. There could be a bug in your current versions. If those were upgraded and no newer updates then downgrade to know working versions unless there were security issues when them.

Brian
 
Old 12-20-2006, 05:36 PM   #3
NSWKim
LQ Newbie
 
Registered: Jul 2006
Distribution: Ubuntu
Posts: 22

Rep: Reputation: 15
Hi,

You might try running a "pstree" or "ps faux" to get an idea of all the threads and what sort of memory they are using. Chances are there's a memory leak in one of the applications. I've also seen problems with bad RAM which make swap fill up to 100% then the machine crashes. You can check you free memory and swap with a "free -m".
 
Old 12-21-2006, 09:20 AM   #4
czamora
Member
 
Registered: May 2006
Posts: 52

Original Poster
Rep: Reputation: 15
Quote:
Originally Posted by Brian1
Have those two programs been updated during the centos upgrade. If so maybe check to see if there are updates for them. There could be a bug in your current versions. If those were upgraded and no newer updates then downgrade to know working versions unless there were security issues when them.

Brian
I have done a complete upgrade of the system, to see if that solved the problem, but did not change anything.
I'm not sure if the httpd version was upgraded during the OS change, but it could be. But I'm not sure how I can downgrade that (I know how to update with "yum upgrade", but always to the last version). Do you know how to downgrade to a specific version?

Thanks.
 
Old 12-21-2006, 09:25 AM   #5
czamora
Member
 
Registered: May 2006
Posts: 52

Original Poster
Rep: Reputation: 15
Quote:
Originally Posted by NSWKim
Hi,

You might try running a "pstree" or "ps faux" to get an idea of all the threads and what sort of memory they are using. Chances are there's a memory leak in one of the applications. I've also seen problems with bad RAM which make swap fill up to 100% then the machine crashes. You can check you free memory and swap with a "free -m".
Mmmm, it seems that during normal operation there are 20 instances of httpd, each consuming 2% of memory (that adds up to 40%). But apart from that, and 3% for mysqld, there are no other processes consuming memory.

The thing is also, if there is a memory leak, it is not continuous, and only shows from time to time (once every other day, more or less). Is that possible?

Thanks.
 
Old 12-21-2006, 02:21 PM   #6
Brian1
Guru
 
Registered: Jan 2003
Location: Seymour, Indiana
Distribution: Distribution: RHEL 5 with Pieces of this and that. Kernel 2.6.23.1, KDE 3.5.8 and KDE 4.0 beta, Plu
Posts: 5,700

Rep: Reputation: 61
Not sure what to check from here.

Brian
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Where is my CENTOS!! hermouche Ubuntu 6 11-09-2006 06:39 AM
CentOS Nix4me Linux - Networking 4 02-06-2006 11:25 PM
Whats the differnce between Centos and CentOS? duffmckagan cAos 1 06-12-2005 12:23 PM
update centos 4 rc1 to centos 4 trou yum? maxut cAos 2 03-04-2005 02:36 AM
CentOS 3.4 [ RHEL 3 ] Wont let go the memory maxboost Linux - Software 0 02-20-2005 10:36 AM


All times are GMT -5. The time now is 03:06 AM.

Main Menu
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration