Abnormal RAM usage in the Truennas virtual machine.

[Would fly]

Currently, I have two virtual machines running on my PVE, one with OpenWRT and the other with TrueNAS. The memory usage of the TrueNAS virtual machine is quite peculiar. After booting up, TrueNAS itself only occupies about 2 GB of memory, and at this point, there is no ARC cache. Regardless of whether I check the memory usage within TrueNAS or the VM Summary, the memory usage is displayed as normal. However, in the Node Summary or when using commands such as 'free', it shows that the TrueNAS virtual machine is utilizing all the memory allocated to it.
Ballooning is turned on, and qemu-guest-agent is running normally.This situation did not occur previously. It arose after I replaced the old equipment and redeployed PVE and TrueNAS. The previous device was based on the Intel N5105 platform, running PVE version 8.2.4 and TrueNAS version 25.04.1. I have now switched to an AMD 5800U platform, with PVE version 8.4.5 and TrueNAS version 25.04.2.
TrueNAS briefly consumes a large amount of memory during startup, after which it stabilizes around 2GB. It seems that PVE does not release this portion of memory; however, I am not entirely certain about this. At least, I do not believe this is an issue with TrueNAS, as they are only separated by a minor version update.
The following screenshot illustrates the abnormal memory usage on my new device.

 

[_gabriel]

it shows that the TrueNAS virtual machine is utilizing all the memory allocated to it

screenshot ?

 

[Would fly]

screenshot ?

+ if there is passthrough into a VM, RAM is fully reserved.

This wasn't the case before. The previous device passthrough the SATA controller, and the new device passthrough 2 NVMe controllers

 

[_gabriel]

what about top within VM ?

 

[Impact]

Please share the Hardware tab of the VM.

 

[Would fly]

Please share the Hardware tab of the VM.

Previously
CPU Motherboard: N5105
RAM: Micron 16Gx2 2400Mhz DDR4 Laptap
SSD: Samsung PM981A 256G
Currently
CPU Motherboard: R7-5800U
RAM: Juhor 32Gx2 3200Mhz DDR4 Laptop
SSD: WD SN730 1T x2 , Micron 5200 eco 960G x1

 

[Impact]

While that is still useful it's not what I asked for. Please read it again

 

[Would fly]

While that is still useful it's not what I asked for. Please read it again
View attachment 88789

 

[Impact]

When you use PCI(e) passthrough ballooning does not work and all the memory is immediately given to the VM.
In this case it might make sense to disable it so you see closer to what you see in top. I also recommend you set up Resource Mapping and enable discard for the virtual disk.