Hi, does xen, or do domUs, somehow remember how much memory they had assigned to them? I've upgraded the memory of the server from 8GB to 36GB (8x4 + 4*1 GB), following the instructions in the manual about how to populate the banks. So far, the server is running fine. I have a VM which used to have 'memory = 3107' in its configuration. When I change the number to 10240 or 8192 or 4096 or even 3110, the VM crashes early during the boot process. Change it back to 3107 and the VM runs fine. There are other domUs that crash when they are booting when I change the amount of memory assigned to them, like from 384MB to 512MB. Change it back to 384MB and the VM runs fine. Only for two or three VMs, I was able to increase the memory. Dom0 and all domUs are running Debian Wheezy. Any idea what's going on here? Am I doing something wrong? The only thing that comes to mind is that for some reason, there's a strange problem with RAM modules of different sizes. But if that's the case, why is the server (IBM x3650 l2g) running fine? -- Again we must be afraid of speaking of daemons for fear that daemons might swallow us. Finally, this fear has become reasonable.