Proxmox 3.2, RAM change is not reflected in guest vm

[da1]

Hello all,

I have a Proxmox 3.2 installed on a Dell optiplex 780, over a 3ware raid1 setup. The machine has 12GB RAM. I have created a Centos x64 VM and initially assigned 4GB of RAM (fixed size memory). After using the vm for some time, more RAM was needed so I turned the vm off, changed the amount of RAM from 4GB to 5GB and power up the vm. To my surprise, the guest OS still detects 4GB RAM. I then did the same but I lowered the amount of RAM to 3GB. After powering up the vm, I could still see 4GB of RAM in /proc/meminfo.

Then, I changed the RAM back to 5GB, stopped the VM and rebooted the proxmox pc. Surely enough, when the vm bootem, I saw 5GB of RAM.



Am I doing something wrong? Can someone reproduce this?

PS: I have also tried different guest OS'es but the problem persists.

 

[da1]

UPDATE:

I've changed the amount of ram to 5GB by selecting "Automatically allocate memory" and setting both the minimum and the maximum to 5GB, rebooted the VM and voila. Interesting workaround.

The funny thing is that now, I\ve set the vm back to "Use fixed size memory" and whatever changes I make, are now being reflected in the vm.


Interesting.

PS: running "qm list" on the cmd line, reports the same amount of ram that was set before i nthe web-interface.

 

[MasterTH]

well, thats quite normal.
the kvm process starts the kvm with the amount of memory you set up in the webinterface. So qm list will show the value of memory you gave the vm as it starts. if you change to not-fixed mode memory is set by the driver inside the kvm.

 

[da1]

You missed the whole point .

 

[stuecki]

You missed the whole point .

Hi!

Cost me half a day to figure out: Ubuntu 12.04 with 3.2.0.80 didn't get more than 1024MB RAM (in proxmox 3.4).

I disabled memory-hotplug (and numa btw.) and the amount of memory is rigt now!

Greetz!

stuecki