Sponsored Content
Full Discussion: Doubt on free command
Top Forums UNIX for Dummies Questions & Answers Doubt on free command Post 302361515 by user7509 on Tuesday 13th of October 2009 11:29:26 AM
Old 10-13-2009
Doubt on free command

All,

I have doubts related to free command in Linux.
My environment is RHEL5 - 64 bit OS
We have 2 node RAC database installed

Query output from node 1 is

Free -g

Total used free shared buffers cached
Mem: 32 25 7 0 5 15
-/+ buffers/cache: 4 27
Swap: 30 0 30

Query output from node 2 is

Free -g

Total used free shared buffers cached
Mem: 32 6 17 0 1 1
-/+ buffers/cache: 4 27
Swap: 30 0 30



We have Oracle database hosted on this server. We are in doubt that actual memory used is 25 GB or 4 GB. Performance team is telling that database is over utilizing the memory of 25 GB. But DB team is telling that actual memory utilization is 4 GB and remaining 20+ GB is used by buffers / cached.

I have googled it and noticed that 25 GB is summation of 4+5+15 (close to 25). I referred Linux material and it says that memory in buffers and cached will improve the performance.

1.Can somebody explain whether actual memory used is 4 GB or 25 GB?
2.What is the use of buffers and cached?
3.Sometimes used value is peaking close to 31 GB from 25 GB. Mostly occupied by buffers and cached.
4.At a particular moment, -/+ buffers/cache: will be same. But Mem used will be more in node 1 and less in node 2. After particular hours, the Mem used will be shifting from node 1 to node 2. i.e., in node 1, Mem used will be 6 GB and Mem used in node 2 will be 25 GB approximately. Any body have any idea about this behaviour?
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Doubt in find command

Hi All, I wanted to list all the files in the current directory which contains the pattern "error". I tried the following grep command grep -i 'error' *.* but i got the error message "ksh: /usr/bin/grep: 0403-027 The parameter list is too long." Any idea why the grep didn't work? Note:... (3 Replies)
Discussion started by: mona
3 Replies

2. AIX

doubt in cal command

I am new to unix... How to get all the saturdays of a specific year? for a specific month, i tried as below.. cal 02 2006 | awk '{print $7}' but it is not giving all saturdays.... can anyone help me with this? Thanks in advance, Sumi (9 Replies)
Discussion started by: sumi
9 Replies

3. UNIX for Dummies Questions & Answers

doubt in tr command

Hi, I am trying to understand a script and found a line as follows: tr '\211\233\240' '\040' < $IN_FILE | tr -cd '\11\12\15\40-\176' > $TEMP_FILE Can any one explain the above line .. What are they trying to translate using the tr command.. I have not used tr command.. so feeling little bit... (2 Replies)
Discussion started by: risshanth
2 Replies

4. Shell Programming and Scripting

Doubt with ftp command

Hi linux experts, I am using ftp command as : ftp hostname but it says unable to connect, if i am using the same in sftp it is working : sftp hostname it works. so please help me how should i use ftp command. (8 Replies)
Discussion started by: salil2012
8 Replies

5. Shell Programming and Scripting

sed command doubt

i have input files like this SFE_DOC_DATE (SFE_DOC_DATE:UniChar.:): "04/18/20" SFE_PSTNG_DATE (SFE_PSTNG_DATE:UniChar.:): "04/18/20" SFE_CREATEDON (SFE_CREATEDON:UniChar.:): "05/31/20" SFE_CLEAR_DATE (SFE_CLEAR_DATE:UniChar.:): "(NULL)" SFE_CLR_DOC_NO... (3 Replies)
Discussion started by: Gopal_Engg
3 Replies

6. Shell Programming and Scripting

One doubt regarding chmod command

which one is correct chmod 777 file.txt or chmod 777 / file.txt what is difference in these two commands? thanx in advance (2 Replies)
Discussion started by: Himanshu_soni
2 Replies

7. Shell Programming and Scripting

command substitution doubt

Hi, I almost always use back quotes in scripts to assigin output of a command to a variable. eg: file=`basename a/b/c/d/file` year_mon=`date +%Y%m` But the same can be achieved like: file=$(basename a/b/c/d/file) year_mon=$(date +%Y%m) I would like to know if there is... (3 Replies)
Discussion started by: wanderingmind16
3 Replies

8. UNIX for Dummies Questions & Answers

Doubt in ls command

dear users and experts, i am stuck withis command and i am unable to understand what is it doing?? ls -d * (7 Replies)
Discussion started by: seshank
7 Replies

9. UNIX for Advanced & Expert Users

Doubt on setserial command

My understanding is that "setserial" command is used to change the attributes of serial device files (ttyS) managed by the linux serial driver(serial module). My doubt is, using setserial command is it possible to change the attributes of other serial device files managed by a different driver... (2 Replies)
Discussion started by: Kesavan
2 Replies

10. Shell Programming and Scripting

Mailx command doubt

hi all, I would need to add the description in the below syntax. let me know the below syntaxt how it can be changed to add the description in the below. ps -ef | grep "server" | mailx -s "servers currently which are running" operational@acel.com Server 62 -> Used for User acessing.... (14 Replies)
Discussion started by: arun888
14 Replies
pbsnodes(8B)								PBS							      pbsnodes(8B)

NAME
pbsnodes - pbs node manipulation SYNOPSIS
pbsnodes [-{a|x}] [-q] [-s server] [node|:property] pbsnodes -l [-q] [-s server] [state] [nodename|:property ...] pbsnodes [-{c|d|o|r}] [-q] [-s server] [-n] [-N "note"] [node|:property] DESCRIPTION
The pbsnodes command is used to mark nodes down, free or offline. It can also be used to list nodes and their state. Node information is obtained by sending a request to the PBS job server. Sets of nodes can be operated on at once by specifying a node property prefixed by a colon. Nodes do not exist in a single state, but actually have a set of states. For example, a node can be simultaneously "busy" and "offline". The "free" state is the absence of all other states and so is never combined with other states. In order to execute pbsnodes with other than the -a or -l options, the user must have PBS Manager or Operator privilege. OPTIONS
-a All attributes of a node or all nodes are listed. This is the default if no flag is given. -x Same as -a, but the output has an XML-like format. -c Clear OFFLINE from listed nodes. -d Print MOM diagnosis on the listed nodes. Not yet implemented. Use momctl instead. -o Add the OFFLINE state. This is different from being marked DOWN. OFFLINE prevents new jobs from running on the specified nodes. This gives the administrator a tool to hold a node out of service without changing anything else. The OFFLINE state will never be set or cleared automatically by pbs_server; it is purely for the manager or operator. -p Purge the node record from pbs_server. Not yet implemented. -r Reset the listed nodes by clearing OFFLINE and adding DOWN state. pbs_server will ping the node and, if they communicate correctly, free the node. -l List node names and their state. If no state is specified, only nodes in the DOWN, OFFLINE, or UNKNOWN states are listed. Specifying a state string acts as an output filter. Valid state strings are "free", "offline", "down", "reserve", "job- exclusive", "job-sharing", "busy", "time-shared", or "state-unknown". -N Specify a "note" attribute. This allows an administrator to add an arbitrary annotation to the listed nodes. To clear a note, use -N "" or -N n. -n Show the "note" attribute for nodes that are DOWN, OFFLINE, or UNKNOWN. This option requires -l. -q Supress all error messages. -s Specify the PBS server's hostname or IP address. SEE ALSO
pbs_server(8B) and the PBS External Reference Specification Local pbsnodes(8B)
All times are GMT -4. The time now is 08:00 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy