[SOLVED] Problem ram allocation on VM

[andmattia]

I've all win machine on my istance affected by memory allocation issue.

I read a lot of post/page but I can't found a root cause of this issue.

This machine is configured with

and from console I see this status


inside of win machine I can see that all ram it used by Driver Locked (Balloon service is enable)



If I disable the service nothing happen inside the VM but on console I don't have correct amount of used RAM.

If I disable "VirtIO Ballon Driver" this status change in this way



ObviouslyI can't see the correct data on console.


Any idea? Someone has the same issue?

I also observe that if I set ram (min & max) value with same data (= no share memory) the VM release virtual dirver memory.

 

[BobhWasatch]

Let me search that for you:

https://forum.proxmox.com/threads/w...after-pve-restart-reboot-with-balloon.141738/
https://forum.proxmox.com/threads/high-memory-buff-cache-on-pve-node.141600/#post-634500
https://forum.proxmox.com/threads/memory-usage-on-proxmox-is-higher-than-vm.141106/#post-631630
https://forum.proxmox.com/threads/d...htop-and-proxmox-overview.138526/#post-618272
https://forum.proxmox.com/threads/proxmox-high-ram-usage.137776/#post-613822
https://forum.proxmox.com/threads/v...icates-large-vm-ram-usage.137256/#post-611354
https://forum.proxmox.com/threads/p...system-is-less-than-250mb.130277/#post-571410

 

[andmattia]

thanks for your search but nothing explain how to use/configure Dynamic Memory (Ballooning).

We came from HyperV and in Hyperv if I set dynamic memory from 1Gb -> 4Gb the host assign max memory to 4Gb. To do the same thing in Proxmox I set dynamic memory from 1 to 4 Gb but from guest I see all memory allocated (unitl reach 90% off avaliable memory) and when application try to start (in same case not all) check available memory and SO say "No memory" because "Driver Locked" VirtIO Balloning consume all space.

The same situation not happen in Linux server. We have some VM the need high memory for limeted time but for the rest not need so we can share but at the moment is not possible to configure the VM to use dynamic but only fixed quantity.

 

[BobhWasatch]

"...but at the moment is not possible to configure the VM to use dynamic but only fixed quantity."

That is correct. You can't do what you did with Hyper-V. Balloon only works to keep host from running out of memory. It activates to take memory from VM's when the host memory becomes full. PVE does not have any feature that corresponds to Hyper-V dynamic memory. Closest thing might be memory hotplug but that only allows manual or scripted add/remove of memory (and guest must support it).

 

[leesteken]

Proxmox simply takes memory away (driver locked) VM memory when total host usage (including ZFS) is 80%, as explained in the PVE manual: https://pve.proxmox.com/pve-docs/pve-admin-guide.html#qm_memory
It does distribute the available memory depending on the relative shares (within the min and max)you configured, but only when host is at 80%.