Proxmox high RAM usage

[Talha]

RAM usage seems to be as much RAM allocated to VM on main server. Anyone know why?

 

[Dunuin]

Are you using ZFS? By default ZFS will use up to 50% of your RAM if you don't manually limit it: https://pve.proxmox.com/wiki/ZFS_on_Linux#sysadmin_zfs_limit_memory_usage

 

[Talha]

Are you using ZFS? By default ZFS will use up to 50% of your RAM if you don't manually limit it: https://pve.proxmox.com/wiki/ZFS_on_Linux#sysadmin_zfs_limit_memory_usage

 

[Talha]

VM is using 98GB RAM in htop.

 

[Dunuin]

And what config you gave your VM? Especially when using PCI Passthrough it will always consume the max RAM you defined for that VM, no matter how much RAM the guest OS actually needs.

 

[Neobin]

Please provide the config (qm config VMID) of the VM in question.

 

[LnxBil]

I wanted to just link my previous post about this, but I could not find it. (BTW: thank you for using the search, I found a ton of good threads about this) ...

* space can be pre-allocated, so the full memory is shown as used, even if the VM sees it differently
* free space inside of a VM is only shown as free (for Windows OS) and that does not mean anything for the guest.
* virtual devices need ram
* the processes around these devices need ram
* the processes around each virtual cpu need ram
* the processes around each VM in general need ram
* disk cache (anything else than none) will need ram (this can be big)