Host Memory used is bigger than the sum of VMs

[andrema2]

Hi all

I'm running Proxmox at a 24 x Intel(R) Xeon(R) CPU E5-2620 v2 @ 2.10GHz (2 Sockets) with 256GB of RAM
Linux versions Linux 5.11.22-3-pve #1 SMP PVE 5.11.22-6
Proxmox pve-manager/7.0-11

Right now I have 5 VMs running. 4 Ubuntu servers, 1x32GB RAM,1x16GB RAM, 1x 4GB/8GB RAM ballooning and 1x 8GB RAM. The other VM is a TrueNas/Freebsd with 32GB of RAM with pass through on the HBA.

The RAM usage at the Proxmox host is 190GB of RAM which is much more than the sum of the VMs above. Besides Freebsd all of them have QEMU guest agent installed and running.

Why is the RAM so much more than the actual sum of the VMs ? Am I doing something wrong ? Should I change some settings ?

Thanks

 

[James Crook]

Hi all

I'm running Proxmox at a 24 x Intel(R) Xeon(R) CPU E5-2620 v2 @ 2.10GHz (2 Sockets) with 256GB of RAM
Linux versions Linux 5.11.22-3-pve #1 SMP PVE 5.11.22-6
Proxmox pve-manager/7.0-11

Right now I have 5 VMs running. 4 Ubuntu servers, 1x32GB RAM,1x16GB RAM, 1x 4GB/8GB RAM ballooning and 1x 8GB RAM. The other VM is a TrueNas/Freebsd with 32GB of RAM with pass through on the HBA.

The RAM usage at the Proxmox host is 190GB of RAM which is much more than the sum of the VMs above. Besides Freebsd all of them have QEMU guest agent installed and running.

Why is the RAM so much more than the actual sum of the VMs ? Am I doing something wrong ? Should I change some settings ?

Thanks

So there are a few more things we (people) need to know. What File systems are you using ?
Have you tweaked the ZFS memory settings ?
How are you seeing how much RAM is used ? the gui, htop, free
What settings do you have on the cache for the disks in the guests ?

I think thats about it but all these will help others answer the question.

 

[Dunuin]

I would guess he is using ZFS and didn't set a ARC limit. In that case the hosts ZFS will use 128GB RAM for the ARC. The FreeNAS VM should always use the full 32GB RAM, so that would be 160GB used RAM. And if the 4 ubuntus use half the 64GB RAM that would explain why 190GB RAM are used.

 

[andrema2]

So there are a few more things we (people) need to know. What File systems are you using ?
Have you tweaked the ZFS memory settings ?
How are you seeing how much RAM is used ? the gui, htop, free
What settings do you have on the cache for the disks in the guests ?

I think thats about it but all these will help others answer the question.

Hi James,

Thanks, sorry newbie.

For the hosts all of them are ZFS, for the ISOs LVM (ex4). I didn't tweaked anything in ZFS. Is there a guide I can read or try to follow ?

I'm using the Proxmox GUI Summary as the measure. I tried top now and I saw the same thing.
I don't have cache set for the disks in the VMs

Thanks for your support

 

[Dunuin]

Look here.