Sponsored Content
Full Discussion: Linux cache
Operating Systems Linux Linux cache Post 302597625 by Shirishlnx on Saturday 11th of February 2012 12:09:58 AM
Old 02-11-2012
Always Pointed..
Your free RAM = free + catched + Buffer (as your catched will going to be utilized when out of sapce )

Code:
 
# free -m
                 total   used       free  shared buffers cached
Mem:              374     108        265    0      9       55
-/+ buffers/cache:        43         330 
Swap:             580      0         580

So here actual free RAM = 265 + 55 + 10 = 330

Yes.. '-/+ buffers/cache: ' is nothing but this value .. but on older version Linux this line is absent so calculate by above formuli ...


To Flush Out Catch and buffer memory ( Do it on your own risk if important application is running on your server live dev)
Code:
 
## Find where is file "drop_caches" in your kernel proc 
 
# find /proc -name drop_caches
/proc/sys/vm/drop_caches 
 
#  sh -c sync; echo 3 > /proc/sys/vm/drop_caches
 
Now see the difference 
 
# free -m
              total       used       free     shared    buffers     cached
Mem:           374         50        323          0          0          9
-/+ buffers/cache:         41        332
Swap:          580         0         580

--Shirish Shukla

Last edited by Shirishlnx; 02-11-2012 at 01:22 AM..
 

10 More Discussions You Might Find Interesting

1. UNIX for Advanced & Expert Users

UBC cache vs. Metadata cache

hi, What is the difference between UBC cache and Metadata cache ? where can i find UBC cache Hits and Metadata cache Hits in hp-ux? Advanced thanx for the help. (2 Replies)
Discussion started by: sushaga
2 Replies

2. UNIX for Advanced & Expert Users

vm and buffer cache

i have a serious doubht about the assignment of memory in hp-ux system . i read from somewhere that the page allocation in hp-ux is not unified unlike compaq . i wanted to know in hp-ux kernel ,once the pages are assigned for the univarsal buffer cache... (2 Replies)
Discussion started by: vish_shan
2 Replies

3. HP-UX

Buffer Cache

What is the "Buffer Cache" used for? (1 Reply)
Discussion started by: ALTRUNVRSOFLN
1 Replies

4. Solaris

ARP Cache

Dear all, We are testing two of our servers for mq series connectivity. The scenario is, when one machine is shutting down it's services there are some scripts that do a dns update, which removes the ip address and relates it to the ip address of the other node on our dns server, and the update... (7 Replies)
Discussion started by: earlysame55
7 Replies

5. Linux

Linux cache

Hi all I am trying to understand the kernel memory management and require assistance in this regard. Kernel first creates the cache memory to perform any subsequent allocation to processes. I could not figure out how it is accomplished. Do kernel directly allocates any hardware cache or allocates... (0 Replies)
Discussion started by: joshighanshyam
0 Replies

6. Programming

Manipulate the Linux ARP Cache in C

Hello, I need help on how to "access" or manipulate the Linux ARP Cache in C, here is the description of the project i'm working in: There are a lot of tools that analize ARP frames and send an e-mail to the sysadmin, that's easy. What i want to do is to inspect every ARP frame that arrives... (18 Replies)
Discussion started by: semash!
18 Replies

7. Linux

getting info on Cache Size, Data Cache etc..

Hi all I saw in Microsoft web site www.SysInternals.com a tool called CoreInfo from able to print out on screen the size of the Data and Instruction caches of your processor, the Locigal to Physical Processor mapping, the number of the CPU sockets. etc.. Do you know if in Linux is available a... (2 Replies)
Discussion started by: manustone
2 Replies

8. UNIX for Advanced & Expert Users

linux memory buffers & cache usage

18:45:47 # free -m total used free shared buffers cached Mem: 96679 95909 770 0 1530 19550 -/+ buffers/cache: 74828 21851 Swap: 12287 652 11635 Hi all. The below output is from a RHEL 4.5... (0 Replies)
Discussion started by: drummerrob
0 Replies

9. Linux

File cache /Page cache Linux

Hi All, could any one point out any open source test-suites for "File cache" testing and as well as performance test suites for the same. Currently my system is up with Linux/ext4. Regards Manish (0 Replies)
Discussion started by: hmanish
0 Replies

10. UNIX for Dummies Questions & Answers

Clearing memory cache on Linux server

i wish to clear memory cache on a production box and i was wondering what is the worst that can happen if i do? i already tested this on a backup server and everything seemed fine. but i need to know from you experts what are the worst things that can happen when i run it on a real server: ... (5 Replies)
Discussion started by: SkySmart
5 Replies
Sys::Statistics::Linux::MemStats(3pm)			User Contributed Perl Documentation		     Sys::Statistics::Linux::MemStats(3pm)

NAME
Sys::Statistics::Linux::MemStats - Collect linux memory information. SYNOPSIS
use Sys::Statistics::Linux::MemStats; my $lxs = Sys::Statistics::Linux::MemStats->new; my $stat = $lxs->get; DESCRIPTION
Sys::Statistics::Linux::MemStats gathers memory statistics from the virtual /proc filesystem (procfs). For more information read the documentation of the front-end module Sys::Statistics::Linux. MEMORY INFORMATIONS
Generated by /proc/meminfo. memused - Total size of used memory in kilobytes. memfree - Total size of free memory in kilobytes. memusedper - Total size of used memory in percent. memtotal - Total size of memory in kilobytes. buffers - Total size of buffers used from memory in kilobytes. cached - Total size of cached memory in kilobytes. realfree - Total size of memory is real free (memfree + buffers + cached). realfreeper - Total size of memory is real free in percent of total memory. swapused - Total size of swap space is used is kilobytes. swapfree - Total size of swap space is free in kilobytes. swapusedper - Total size of swap space is used in percent. swaptotal - Total size of swap space in kilobytes. swapcached - Memory that once was swapped out, is swapped back in but still also is in the swapfile. active - Memory that has been used more recently and usually not reclaimed unless absolutely necessary. inactive - Memory which has been less recently used and is more eligible to be reclaimed for other purposes. On earlier kernels (2.4) Inact_dirty + Inact_laundry + Inact_clean. The following statistics are only available by kernels from 2.6. slab - Total size of memory in kilobytes that used by kernel for data structure allocations. dirty - Total size of memory pages in kilobytes that waits to be written back to disk. mapped - Total size of memory in kilbytes that is mapped by devices or libraries with mmap. writeback - Total size of memory that was written back to disk. committed_as - The amount of memory presently allocated on the system. The following statistic is only available by kernels from 2.6.9. commitlimit - Total amount of memory currently available to be allocated on the system. METHODS
new() Call "new()" to create a new object. my $lxs = Sys::Statistics::Linux::MemStats->new; It's possible to set the path to the proc filesystem. Sys::Statistics::Linux::MemStats->new( files => { # This is the default path => '/proc', meminfo => 'meminfo', } ); get() Call "get()" to get the statistics. "get()" returns the statistics as a hash reference. my $stat = $lxs->get; EXPORTS
No exports. SEE ALSO
proc(5) REPORTING BUGS
Please report all bugs to <jschulz.cpan(at)bloonix.de>. AUTHOR
Jonny Schulz <jschulz.cpan(at)bloonix.de>. COPYRIGHT
Copyright (c) 2006, 2007 by Jonny Schulz. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. perl v5.14.2 2012-03-09 Sys::Statistics::Linux::MemStats(3pm)
All times are GMT -4. The time now is 04:15 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy