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{{Warning|The information below is obsoleted, you should just use [[VSwap]].}}
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{{UBC toc}}
  
 
[http://forum.swsoft.com/showthread.php?threadid=26770 This thread] has been summarized here on this page.
 
[http://forum.swsoft.com/showthread.php?threadid=26770 This thread] has been summarized here on this page.
 
To keep it simple as close to the original format, it is in the form of questions and answers.
 
To keep it simple as close to the original format, it is in the form of questions and answers.
  
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=== Question: I want to know how much RAM is allocated to a particular container. I ran cat /proc/user_beancounters from inside my container and I have the following results below. But I am not sure how to interpret the results. ===
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=== Question: I want to know how much RAM is allocated to a particular VE. I ran cat /proc/user_beancounters from inside my VPS and I have the following results below. But I am not sure how to interpret the results. ===
  
 
<code>
 
<code>
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             oomguarpages      59239      59367    125000 2147483647          0
 
             oomguarpages      59239      59367    125000 2147483647          0
 
</code>
 
</code>
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The guarantee is vmguarpages barrier = 125000 pages. In any case, the container will be able to allocate that size of memory. Well... in almost any case, with one exception...
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The guarantee is vmguarpages barrier = 125000 pages. In any case, the VPS will be able to allocate that size of memory. Well... in almost any case, with one exception...
  
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...when the whole node is in out of memory situation. In that case, the guarantee is oomguarpages barrier (the same 125000 pages in this example). It means that no container process will be killed if memory usage by the container is less than 125000 * 4096 bytes. If it is more, some process can be killed, and failcounter of oomguarpages will be increased.
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...when the whole node is in out of memory situation. In that case, the guarantee is oomguarpages barrier (the same 125000 pages in this example). It means that no VPS process will be killed if memory usage by the VPS is less than 125000 * 4096 bytes. If it is more, some process can be killed, and failcounter of oomguarpages will be increased.
  
 
Maximum size of memory which can be allocated is defined by privvmpages (see my previous post).
 
Maximum size of memory which can be allocated is defined by privvmpages (see my previous post).
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You are a bit wrong here. Let me explain it more carefully.
 
You are a bit wrong here. Let me explain it more carefully.
  
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vmguarpages barrier is a guarantee: in any case (except out-of-memory aka OOM) you will be able to allocate 125000 pages. Well, probably you will be able to allocate more, up to 750000 pages (and if you are cool high priority process, you will be able to allocate 825000 pages, but definitely not more). We don't say anything about RAM or SWAP here. These pages can be swapped by HWnode kernel if needed, and can live in RAM if possible. Frankly, you can't say "I want this container to have X MB RAM and Y MB SWAP". There is no such parameter.
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vmguarpages barrier is a guarantee: in any case (except out-of-memory aka OOM) you will be able to allocate 125000 pages. Well, probably you will be able to allocate more, up to 750000 pages (and if you are cool high priority process, you will be able to allocate 825000 pages, but definitely not more). We don't say anything about RAM or SWAP here. These pages can be swapped by HWnode kernel if needed, and can live in RAM if possible. Frankly, you can't say "I want this VPS to have X MB RAM and Y MB SWAP". There is no such parameter.
  
 
vmguarpages does not account anything, so its current usage always equals to zero.
 
vmguarpages does not account anything, so its current usage always equals to zero.
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oomguarpages parameter's 'current usage' field accounts total amount of RAM+SWAP used.
 
oomguarpages parameter's 'current usage' field accounts total amount of RAM+SWAP used.
  
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physpages parameter accounts total amount of RAM used by the container (the memory shared between containeres is divided and accounted in physpages for all containeres which use it in equal fractions). It cannot be limited, it just shows the current situation.
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physpages parameter accounts total amount of RAM used by the VPS (the memory shared between VPSes is divided and accounted in physpages for all VPSes which use it in equal fractions). It cannot be limited, it just shows the current situation.
  
 
Let's do some math here.
 
Let's do some math here.
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kmemsize current value: 5125208 bytes
 
kmemsize current value: 5125208 bytes
  
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the sum is 247869844 bytes. If this sum is more than oomguarpages barrier = 125000 pages = 512000000 bytes (it is not), some of the processes on the container can be killed in case of OOM situation.
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the sum is 247869844 bytes. If this sum is more than oomguarpages barrier = 125000 pages = 512000000 bytes (it is not), some of the processes on the VPS can be killed in case of OOM situation.
  
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=== Question: Is there a way to know for a container account holder (me) that a server has reached an OOM situation? ===
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=== Question: Is there a way to know for a VPS account holder (me) that a server has reached an OOM situation? ===
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'free' inside a container will show memory statistics for the hardware node (total memory, used memory, total swap, used swap). It's OK for Linux system to use as much RAM as possible, so free memory size is going to be not more than a few megabytes.
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'free' inside a VPS will show memory statistics for the hardware node (total memory, used memory, total swap, used swap). It's OK for Linux system to use as much RAM as possible, so free memory size is going to be not more than a few megabytes.
  
 
=== Are you aware of a script that would run as a cron job and do the OOM math on a regular basis and email me if I've hit the red zone or maybe at 85-90%? ===
 
=== Are you aware of a script that would run as a cron job and do the OOM math on a regular basis and email me if I've hit the red zone or maybe at 85-90%? ===
 
We don't have such script but you can just take a look at the last column of /proc/user_beancounters. Nonzero values there mean that resource allocations were rejected.
 
We don't have such script but you can just take a look at the last column of /proc/user_beancounters. Nonzero values there mean that resource allocations were rejected.
  
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<pre>Rojoblandino wrote:
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=== Can you please elaborate the difference between oomguarpages and privvmpages?===
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Thank you for everything, unfortunately the only way I have to help is to work with code,
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Both seem to be showing mem + swap. Is the difference between two about allocated but not used pages? I mean, privvmpages show allocated (some of which might not be used) for mem + swap, whereas oomguarpages show allocated, all of which are used, mem + swap? ====
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I leave something here that I hope you will enjoy and see it very usefull. And yes there
 
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was not any script but now there is one. Greetings and have fun.</pre>
 
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<pre>
 
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#!/bin/bash
 
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# Openvz Containers Memory Status
 
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# Version 1.5
 
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# Reference: http://wiki.openvz.org/Setting_UBC_parameters
 
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# The program is placed under the GNU Public License (GPL)
 
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# Author: Roberto Blandino Cisneros.
 
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# Under any change please notify me
 
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# rojoblandino(at)yahoo.com
 
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# Advantages or changes:
 
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# 1) Calculation of vz containers.
 
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# 2) Percentage Calculation.
 
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# 3) Avoid simples wrong characters and out of range entry.
 
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# 4) Use the same same order of vzlist output.
 
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# 5) Problems on vzid param mistakes fixed.
 
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# 6) Fixed when 0 passed by param an error appear
 
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# The usage of this script is easy.
 
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# To understand how it works first you must know
 
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# the quantity of your containers so it is the
 
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# first thing we do.
 
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# Each container get a number if you have three
 
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# containers e.g. eva gira huna
 
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# Depending of the order ar shown in
 
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# /proc/user_beancounters that number of position
 
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# will be taken.
 
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# If eva, gira and huna containers are shown in that
 
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# order they will be 1 2 and 3 respectively.
 
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# Is so simple like that, then if you want to see
 
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# the status for gira container you must type in
 
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# your shell:
 
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# $> bash vmstatus.sh 2
 
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# And you will see the status of this container.
 
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# First thing to do is to get the list of containers
 
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vzn=$(($(vzlist | wc -l)-1))
 
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case $# in
 
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    1)
 
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        # Get the container to be calculated
 
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        vm_param=$1
 
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        # Just avoiding our human error
 
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        datachk=$(echo $vm_param | grep -e [a-z] | wc -l)
 
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        if let "datachk>0";then
 
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                printf "That's not a valid number!\n"
 
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                exit
 
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        fi
 
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        # Avoiding another mistake maybe the user forgot the quantity of vm allocated
 
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        if let "vm_param>vzn";then
 
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                printf "Container out of range, please try a number between 1 and %d\n" "$vzn"
 
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                exit
 
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elif let "vm_param==0";then
 
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printf "This value is not available, value must be higher than 0 \n"
 
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exit
 
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        fi
 
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        # Take the real position of the container to get from the vzlist
 
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        # for avoiding the first line we add one line more, this mean that id
 
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        # will be taken from the 2nd line ahead
 
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        let $vm "vm=vm_param+1"
 
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        # Uncomment this and comment the line above if you want to switch the order
 
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        # let $vm "vm=(n-vm_param)+2"
 
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        # Take the id from the vzlist output
 
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        id_vm=$(vzlist | head -$vm | tail -1|awk '{print $1}')
 
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        # Get the line where is located the vm to be calculated
 
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        val=$(grep -n $id_vm /proc/user_beancounters | awk -F: '{print $1}')
 
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        # Adding the 23 block where the info is located
 
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        let $val "val=23+(val)"
 
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        # If you want to see all values of the vm uncomment this
 
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        #head -$val /proc/user_beancounters  | tail -24
 
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        # The math start here.
 
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        # To understand what i am doing here i will repeat again that
 
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        # you must read carefully the page http://wiki.openvz.org/Setting_UBC_parameters
 
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        # the only thing i do was to get the values explained already there.
 
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        kmemsize=$(head -$val /proc/user_beancounters | tail -24 | head -1 | tail -1 | awk '{print $3}')
 
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        oomguarpages=$(head -$val /proc/user_beancounters | tail -24 | head -9 | tail -1 | awk '{print $2}')
 
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        tcpsndbuf=$(head -$val /proc/user_beancounters | tail -24 | head -14 | tail -1 | awk '{print $2}')
 
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        tcprcvbuf=$(head -$val /proc/user_beancounters  | tail -24 | head -15 | tail -1 | awk '{print $2}')
 
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        othersockbuf=$(head -$val /proc/user_beancounters | tail -24 | head -16 | tail -1 | awk '{print $2}')
 
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        dgramrcvbuf=$(head -$val /proc/user_beancounters | tail -24 | head -17 | tail -1 | awk '{print $2}')
 
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        oomguarpages_barrier=$(head -$val /proc/user_beancounters | tail -24 | head -9 | tail -1 | awk '{print $4}')
 
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        # Three current values need to be calculated:
 
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        # oomguarpages current value (MEM+SWAP actual usage)
 
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        # socket buffers current value
 
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        # kmemsize current value
 
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        let $resp "resp=((oomguarpages*4096)+tcpsndbuf+tcprcvbuf+othersockbuf+dgramrcvbuf+kmemsize)"
 
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        # Calculating the oom Barrier
 
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        let $oom "oom=(oomguarpages_barrier*4096)"
 
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        # Getting the percentage of the output
 
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        let $porc "porc=(resp*100)/oom"
 
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        # Showing the ID and Percentage of the container
 
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        #echo $(head -$val /proc/user_beancounters | tail -24| head -1 | awk -F: '{print $1}')" Status: "$porc"%"
 
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        printf "%s Status: %d %%\n" "$(head -$val /proc/user_beancounters | tail -24| head -1 | awk -F: '{print $1}' | sed "s/^\ *//g")" "$porc"
 
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        # Showing the two important values.
 
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        string1="System Count:"
 
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        string2="OOM Barrier:"
 
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        ls1=${#string1}
 
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        ls2=${#resp}
 
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        if let "ls1<ls2";then
 
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          let $ls3 "ls3=ls2-ls1"
 
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          for (( i=0;i<$ls3;i++ ));do
 
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            space_line=$space_line" "
 
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          done
 
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          printf "System Count:%s\t-\tOOM Barrier:\n" "$space_line"
 
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          printf "%s\t-\t%s\n" "$resp" "$oom"
 
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        elif let "ls1>ls2";then
 
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          let $ls3 "ls3=ls1-ls2"
 
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          for (( i=0;i<$ls3;i++ ));do
 
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            space_line=$space_line" "
 
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          done
 
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          printf "System Count:\t-\tOOM Barrier:\n"
 
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          printf "%s%s\t-\t%s\n" "$resp" "$space_line" "$oom"
 
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else
 
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          printf "System Count:\t-\tOOM Barrier:\n"
 
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          printf "%s\t-\t%s\n" "$resp" "$oom"
 
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        fi
 
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        # Uncoment this if you just want to now if it is below to barrier
 
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        # it means is healthy if resp is less than oom
 
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        # if let "resp<oom";then
 
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        # Or let the following if you want to evaluate as a percentage
 
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        # 75% is by default you must change it to your own warning barrier.
 
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        if let "porc<75";then
 
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            echo "It is ok!"
 
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        else
 
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            echo "Some of the processes will be killed!"
 
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        fi
 
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        ;;
 
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    *)
 
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        echo "Just one parameter is allowed for this script"
 
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        echo "e.g. "$0" 1 "
 
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        ;;
 
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esac
 
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</pre>
 
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=== Can you please elaborate the difference between oomguarpages and privvmpages? ===
 
−
 
 
−
Both seem to be showing mem + swap. Is the difference between two about allocated but not used pages? I mean, privvmpages show allocated (some of which might not be used) for mem + swap, whereas oomguarpages show allocated, all of which are used, mem + swap?
 
−
 
 
 
==== Answer: ====
 
==== Answer: ====
 
Yes, oomguarpages current value shows actual usage of MEM+SWAP.
 
Yes, oomguarpages current value shows actual usage of MEM+SWAP.

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