Strange behavior of memory in openvz container

[jhd]

Hello everyone!
I'm trying to understand the use of memory and Proxmox openvz containers.
I have installed on a server with 8 cores and 8 Gg ram one openvz container with 3 cores and 2 GB of RAM allocated , it has a zentyal 3.3
(installed from a template ubuntu 12.04 ).
This machine is used only as a file server with less than 60 concurrent users (although sometimes a bit heavy files are moved from/to the server).
The curious point is that when I arrive in the morning and are not no users online, the resume tab of the zentyal and the result of "free -m" command via ssh to zentyal, consumption showed is over 90 % of these 2Gb. When I increase the memory of Vz Containerto 4Gb it begins using 2Gb memory and gradually throughout the day is increasing the use of RAM until it is above 90 % usage.


Every time I make this operation (resize of the container to 2Gb RAM and after back up to 4Gb) and same thing happens.


Is this normal in openvz or may I have made ​​an error in the setup?


Thanks!
J.:.

 

[thheo]

Can you check for what is the RAM used? maybe is caching ? then it is normal.. it would cache as much as possible, but it would
free as soon as some process needs ram

 

[jhd]

Yes is thheo the memory is caching

             total       used       free     shared    buffers     cached
Mem:       4194304    4112600      81704          0          0    3813908
-/+ buffers/cache:     298692    3895612
Swap:      8388608     838216    7550392
Total:    12582912    4950816    7632096

Is it posible to know what part of used memory is used by the system and what part is just cached?
Is it posible to manage how much memory is cached?

Thanks a lot!

 

[thheo]

Is this output from the host or the container?

 

[jhd]

Sorry I thank that I request this post :/

Is this output from the host or the container?

The output from the container:

             total       used       free     shared    buffers     cached
Mem:       4194304    4105784      88520          0          0    3339952
-/+ buffers/cache:     765832    3428472
Swap:      8388608     833096    7555512

The output from the proxmox:

             total       used       free     shared    buffers     cached
Mem:       8130520    7998624     131896          0    1156424    3868532
-/+ buffers/cache:    2973668    5156852
Swap:      4194296     292444    3901852

I was testing this days and the performance of the server and it's ok. I was borry because any peaks of memory use, but it coincided with operations of massive change of permissions that makes zentyal 3.3 recursively when I touched the ACLs of a folder with a lot of content. Now looks stable.