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Question

Tuning (memory) Media Agent Linux

  • 25 September 2023
  • 5 replies
  • 264 views
F
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Hello,

 

Could you tell me which parameters to set for a RHEL 7.9 Linux media-agent, particularly for memory ?

Is there anything to set with swap ?

 

Regards,

Fabrice

5 replies

Arunkumar P
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Hi @F@bEDF ,

 

Good day! 

 

What kind of parameter you’re looking for? 

 

For swap partition, The preferred size for a swap partition is twice the amount of physical memory available on the system. If this is not possible, then the minimum size should be the same as the amount of memory installed.

F
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Badge +1

Hi Arunkumar P,

 

Thank for your reply.

We use a lot of memory and huge usage of swap, on our Linux media agents and I'm looking for a value that Commvault might recommend.
For example for the swapiness value but not only.

 

Regards.

 

V
Rank
Badge +1

Hello!

Also wanted to ask about this.

RHEL 8.7, 512G RAM. just set 16G swap as was sure that it’s never gonna be used.

In fact seeing this:

[root@cmv-app21-lp2 ~]# free -h
              total        used        free      shared  buff/cache   available
Mem:          503Gi        14Gi       2.5Gi       224Mi       486Gi       484Gi
Swap:          15Gi        15Gi       0.0Ki

[root@cmv-app21-lp2 ~]# find /proc -maxdepth 2 -path "/proc/[0-9]*/status" -readable -exec awk -v FS=":" -v TOTSWP="$(cat /proc/swaps | sed 1d | awk 'BEGIN{sum=0} {sum=sum+$(NF-2)} END{print sum}')" '{process[$1]=$2;sub(/^[ \t]+/,"",process[$1]);} END {if(process["VmSwap"] && process["VmSwap"] != "0 kB") {used_swap=process["VmSwap"];sub(/[ a-zA-Z]+/,"",used_swap);percent=(used_swap/TOTSWP*100); printf "%10s %-30s %20s %6.2f%\n",process["Pid"],process["Name"],process["VmSwap"],percent} }' '{}' \;  | awk '{print $(NF-2),$0}' | sort -hr | head | cut -d " " -f2-
find: ‘/proc/463886’: No such file or directory
   4060154 cvd                                     11438760 kB  68.18%
   4060159 CvMountd                                  840636 kB   5.01%
   3356965 packagekitd                               656912 kB   3.92%
   4060167 dotnet                                    318980 kB   1.90%
      4716 metricbeat                                 45684 kB   0.27%
   3356976 rhsm-service                               29544 kB   0.18%
   1236809 puppet                                     25980 kB   0.15%
    113725 CVODS                                      22464 kB   0.13%
      2298 systemd-journal                            17528 kB   0.10%
   4060156 cvfwd                                      17508 kB   0.10%

More than a half of the swap is ocupied with commvault.

[root@cmv-app21-lp2 ~]# sysctl vm.swappiness
vm.swappiness = 10

Neither swap = ram*2 nor swap = ram is not possible in my environment due to 460 GB SSD for the OS and application.

 

Rajiv
Rank
Userlevel 4
Badge +11

Hello @F@bEDF @Vladi9011 

I believe we don’t have any additional setting specifically to control RAM usage. However if a lot of memory is being used on your server specifically by Commvault processes, its better to open a case with us and we can check for the reasons behind it and give you recommendations accordingly. 

Secondly @Vladi9011 I see that you have 484 G memory available but free memory is only 2.5G? This looks weird. If you are going out of RAM only then the applications running on OS will use Swap memory of your system which is also not a good practice. If you have actual RAM available on the system and still the applications are using swap memory, please get it checked with your OS vendor further. 

Best,

Rajiv Singal

V
Rank
Badge +1

Hi, @Rajiv,

Regarding a free memory we should see it roughly as available = free.

Here is the explanation. So i don’t see any good reason so far for Commvault software to use swap.

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