Support LQ: Use code LQ3 and save $3 on Domain Registration
Go Back > Forums > Linux Forums > Linux - General
User Name
Linux - General This Linux forum is for general Linux questions and discussion.
If it is Linux Related and doesn't seem to fit in any other forum then this is the place.


  Search this Thread
Old 10-09-2009, 05:47 AM   #1
amit shukla
LQ Newbie
Registered: Oct 2009
Posts: 2

Rep: Reputation: 0
kernel 2.6.9-89.0.9.ELsmp related question

We are currently on the kernel version 2.6.9-89.0.9.ELsmp and we have seen cases of cache usage going very high.(almost till the level of total available memory)
To solve this issue we used the following command:

echo 3 > /proc/sys/vm/drop_caches

The result is that it drops clean caches, dentries and inodes from memory, causing that memory to become free.

The man pages on the proc displays that drop_caches is available since the kernel version 2.6.16.
refert to the url below :

However as stated earlier drop_caches works on kernel version 2.6.9-89.0.9.ELsmp as well.
How can it be confirmed if its a safe option to use drop_caches in 2.6.9-89.0.9.ELsmp or
is any other source from where this can be verified ?

Thanks in advance.
Old 10-09-2009, 05:59 AM   #2
Registered: Jan 2005
Location: Shropshire, England, UK
Distribution: RedHat, Fedora, CentOS..........
Posts: 121

Rep: Reputation: 19
I would question as to why this is a problem. generally Linux will utilise free memory for caching (and other tasks) to help improve performance and responsiveness. Should an application need the memory held by the cache the kernel will release it as required.

What in your setup requires that the memory be left unused (ie. free) rather than being utilised for caching to help with overall system performance ?
Old 10-09-2009, 09:00 AM   #3
Senior Member
Registered: May 2006
Location: USA
Distribution: Debian
Posts: 4,694

Rep: Reputation: 566Reputation: 566Reputation: 566Reputation: 566Reputation: 566Reputation: 566
This is not a problem.

RHEL kernels may have the old numbers but they are closer to the newer kernels, really.


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 On
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Change kernel loaded from 2.6.9-55.ELlargesmp to 2.6.9-55.ELsmp Farmer Baker Linux - Newbie 2 03-13-2008 09:42 AM
Where will I get RHEL3 with kernel 2.4.21-27.Elsmp hsmukunda Linux - Newbie 2 11-17-2006 10:40 AM
java crashes on 2.4.21-20.ELsmp kernel rvmoye Red Hat 1 12-16-2004 02:01 PM
mkinitrd kernel-related question Tino27 Slackware 1 03-26-2004 11:14 PM
module related question when compiling kernel taoweijia Linux - Newbie 1 02-10-2004 04:31 PM

All times are GMT -5. The time now is 04:06 AM.

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