Comment by itm-mra for Can you check the following - which will tell us what problem do you have? 1. Login as admin 2. Under Admin tab - check the Hypervisors and see what does it report as RAM (used) and RAM (total) - This should tell us what is the hypervisor reporting On my environment I tried to recreate your problem by creating an instance with memory more than available in the Hypervisor and I got exactly the same errors on dashboard, nova-conductor and nova-scheduler logs. So I definitely think whatever memory is reported by your hypervisor - you are trying to launch instance with more memory than that. Update1 to my answer for your update You said you have some 250 GB memory on your server - can you confirm whether this understanding is correct? Because if you really have 250 GB physical memory on your server but hypervisor is reporting only 4 GB - I suspect you may have installed 32 bit version of Ubuntu OS and hence it can actually able to use/see only 4 GB. You can check using uname -a and see if it reports as i386 or as x86_64. If its i386 meaning you have installed 32 bit OS, then the only option is reinstall with 64 bit OS and then install Openstack again. If you have 64 bit OS, then ideally the OS/Hypervisor should report the entire physical memory and not just 4 GB. So my analysis of your situation is that either you have install 32 bit OS or you actually have only 4GB in your server and not 250GB as you initially mentioned. Update 2 When Openstack creates an instance, in the backend (as you are using libvirt) libvirt creates instances, however I have seen the names to be something like instance-0000000c etc (which are the VMs created by libvirt - KVM/qemu in the backend) and not the actually names you see in Horizon. Have you used your 250GB server to create your Openstack node as a VM itself by the name ubuntu-machine-1 or so. and then have installed openstack in that ubuntu-machine-1 as your Hypervisor thus showing 4GB as memory which is what is allocated to ubuntu-machine-1. Is this correct? If that's the case you may want to increase the memory allocated your Hypervisor [which itself is a VM] using virsh command - see link http://earlruby.org/2014/05/increase-... Restart your Hypervisor and then check again.

Here is my output: `$ uname -a Linux VERA02 3.16.0-36-generic #48~14.04.1-Ubuntu SMP Wed Apr 15 13:11:28 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux` Free -g reports 251 total and 190 free.