memory consumed suddenly increases inspite of no activity taking place.. [message #8617] |
Wed, 29 November 2006 12:59 |
sanjooz_2002
Messages: 19 Registered: October 2006
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Junior Member |
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Hi,
I am a newbee. So, kindly bear with me if this sounds silly. I have created 4 virtual servers (all running centos) on a main hardware node (which has got centos). I am using 1GB RAM. Recently I found a strange anamoly in the RAM space utilization. After I booted the main hardware node I did a "free -m" and found this:
total used free shared buffers cached
Mem: 942 535 406 0 106 209
-/+ buffers/cache: 219 723
Swap: 1919 0 1919
After some time (approx half an hour), inspite of no activity taking place on the machine, I found the following by using the free -m command:
total used free shared buffers cached
Mem: 942 536 406 0 106 209
-/+ buffers/cache: 219 723
Swap: 1919 0 1919
I tried it again after an hour, and again I found the memory utilization increasing.
total used free shared buffers cached
Mem: 942 537 405 0 107 210
-/+ buffers/cache: 219 723
Swap: 1919 0 1919
It keeps increasing this way, although the system is idle.
I have read few articles suggested in the forum (FAQ) like the foll:
http://gentoo-wiki.com/FAQ_Linux_Memory_Management
But, I really doubt if this is the case because the cache and buffer size are the same and only the amount of memory getting utilzed is increasing.
The only thing that is puzzling me is this that, if there is no activity taking place on my system, how come the memory utilized is increasing???
Can anyone help me in this regard????Thanks in advance!!!
[Moderator: added CODE tags to read free output more easy]
[Updated on: Wed, 29 November 2006 13:20] by Moderator Report message to a moderator
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Re: memory consumed suddenly increases inspite of no activity taking place.. [message #8619 is a reply to message #8617] |
Wed, 29 November 2006 13:23 |
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You can only be sure that there is no activity if you will switch to runlevel 1 and check there are no other processes than init. Otherwise, you certainly have crond, syslogd, sshd and a few other services running -- and they do something from time to time. More to say -- since you have 4 VEs running, they also have crond, syslogd and some other stuff which is running and doing something.
And what you see does not mean there is memory leak or smth. To my mind, it's quite normal.
Kir Kolyshkin
[Updated on: Wed, 29 November 2006 13:24] Report message to a moderator
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Re: memory consumed suddenly increases inspite of no activity taking place.. [message #8625 is a reply to message #8617] |
Wed, 29 November 2006 16:57 |
rickb
Messages: 368 Registered: October 2006
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Senior Member |
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For your question about used ram, disregard all lines from 'free -m' except:
-/+ buffers/cache: 219 723
The linux kernel will move data from ram to swap or vice versa and also buffer file reads to try and optimize the overall system. This explains why the values can change despite very little userspace activity. The line above tells you how much ram you have left for allocation by software in your HN and your VEs. This is your main concern. Its good to have extra memory laying around for disk buffers but its not required for your software to function.
When I look at your three free outputs, I only see a few changed values and by only a few megs of ram. This really is nothing to be concerned about.
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