Questions about ballooning

[fork]

Hi,

I'm wondering about how Ballooning actually used in Proxmox.

Scenario: I'm a quite experienced system administrator, but proxmox is new for me. I have a setup with two servers using proxmox ve 4.1 in Non-HA Clustermode with 2 regular nodes and one dummy node for quorum with drbd on the regular nodes. I'm using only KVM/QEMU at the moment.

In my general understanding and after reading some documents about this, ballooning is a manual process, which eats a specified amount of ram, which is then given back to the host system.

Is there a ballooning management in proxmox, that manages dynamic assignment of ballooning automatically "in a desired way"? To be more specific: My Use-Case is the following:

I have a number of Virtual Machines - say 4 - that got assigned a memory range within 4 GB and 16 GB of RAM on a host system that's equipped with 32 GB RAM. Each one of those Machines temporarily needs the whole 16 GB.

So my question is: Is there a ballooning management in Proxmox that pulls memory from the machine that did need the full 16 GB memory in the past, so that real memory is now available for the machine which needs the memory now?

Thanks for reading my question.

 

[dietmar]

Is there a ballooning management in proxmox, that manages dynamic assignment of ballooning automatically "in a desired way"?

ballooning is managed by pvestatd - here is a link to the code:

https://git.proxmox.com/?p=pve-mana...f8809f1511bfc00ad6afbe0bf5f9fba7;hb=HEAD#l130

 

[fork]

Thanks for the link Dietmar.

As far as I understand the code, Automatic Ballooning ist done as soon as 80% RAM usage of the host is reached every 10 seconds(update_time) for a max. balloon inflating size of 100 MB(maxchange) per VM?

 

[dietmar]

As far as I understand the code, Automatic Ballooning ist done every 10 seconds(update_time) for a max. balloon inflating size of 100 MB(maxchange) per VM?

yes, something like that.