RAM memory above 80%

[willamis]

Hello,

server with 32GB of memory and made 16GB available for the VM. But in the web interface it shows the graph with memory above 80%. Can someone explain to me why this is happening?

 

[Dunuin]

Do you maybe use ZFS (BKP-ONE / BPK-TWO?) or did you enable a caching mode for your VMs other then "none"?

free -h, top and arc_summary might help to see whats going on.

 

[B.Otto]

Thats the display of the VM. Since most modern Operating Systems use their 'free' RAM for caching, the VM shows a high RAM usage.

Generaly, the Hypervisor can't differentiate 'from the outside' whether thos 95% of RAM are actually in use for programs inside the VM or just kept 'warm' by the OS for caching.

 

[willamis]

Você talvez use ZFS (BKP-ONE / BPK-TWO?) ou você habilitou um modo de cache para seus VMs outros então "nenhum"?

free -h, top e arc_summary podem ajudar a ver o que está acontecendo.

BKP-ONE / BPK-TWO is VM backup storage proxmox backup server

 

[willamis]

Thats the display of the VM. Since most modern Operating Systems use their 'free' RAM for caching, the VM shows a high RAM usage.

Generaly, the Hypervisor can't differentiate 'from the outside' whether thos 95% of RAM are actually in use for programs inside the VM or just kept 'warm' by the OS for caching.

Does it mean it's normal?

 

[Dunuin]

Jup., thats normal. OSs will eat every bit of RAM you throw at them.
In case thats a Windows VM you should install the virtio drovers and the QEMU guest agent. With that it won't show cached RAM as used RAM.

 

[willamis]

Jup., thats normal. OSs will eat every bit of RAM you throw at them.
In case thats a Windows VM you should install the virtio drovers and the QEMU guest agent. With that it won't show cached RAM as used RAM.

The VM is Linux Ubuntu

 

[leesteken]

The VM is Linux Ubuntu

Enable the balloon device (even when not using it) in the VM settings and install the QEMU guest agent (sudo apt install qemu-guest-agent) in Ubuntu and enable it in the VM settings. And stop and restart the VM.