Hi Vladimir, You might also need to check the flags given in nova.conf for virtual-memory, virtual-cpu to physical-memory, physical-cpu mapping. If not specified in nova.conf, default value is taken for them. You can have a look at table 5.22 on this link:- http://docs.openstack.org/essex/openstack-compute/admin/content/compute-options-reference.html
For eg, as per the table, "ram_allocation_ratio=1.5", this statement states that virtual memory used by all the instances combined can be 1.5*(physical memory) present on the system. Similarly, the ratio for CPU's is 1:16 but its customizable with those flags. Thanks and Regards Rahul Sharma On Wed, Aug 28, 2013 at 5:14 PM, <[email protected]> wrote: > That depends on how big the VM is, and what over subscription rate you're > running out. > > Generally RAM is going to be your limiting factor, it is fairly easy to > over subscribe CPU, and if you're disk is really unlimited, that isn't > going to stop you either. > > Assuming you're not oversubscribing RAM, you'll need to account for the > overhead of your operating system and various services, KVM overhead etc, > say 8-12GB. Subtract that out of your RAM number. > > Then divide by the amount of RAM your base VM has, and that would be how > many you could (theoretically) run. Your CPU over subscription rate would > then play in as a factor of how many of those is really possible. > > More importantly -- try it out and see where it breaks! Nothing like a > good load test. > > > Hello! > > I'm starting to deploy a private cloud on OpenStack! As the hypervisor > > I use nova+KVM on Centos 6.4. > > Tell me how to count how many virtual machines can be placed on a single > > KVM node. > > How to count the number of virtual machines on single node to get > > everything working perfectly? > > > > Hardware configuration: > > CPU: 2x Intel(R) Xeon(R) CPU E5-2609 @ 2.40GHz - 4 core > > RAM: 96 GB > > HDD:Unlimited > > HW: ProLiant BL460c > _______________________________________________ > Mailing list: > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack > Post to : [email protected] > Unsubscribe : > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack >
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