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Re: Memory quota in nova-compute nodes.


On Thursday, January 19, 2012 at 12:52 PM, Jorge Luiz Correa wrote:

> I would like to know if it's possible to configure quota in each nova-compute node. For example, I set up a new hardware with 8 GB of memory and install the nova-compute, but I wish only 4 GB of memory are used (dedicated to nova-compute). Is it possible? If so, how can I configure that?
> I've seen quotas in projects, configured using nova-manage command line tool. But it isn't what I'm looking for. 
In Essex, you can use 'reserved_host_memory_mb' with the ZoneManager to reserve a certain amount of memory per host.

If you're on Diablo, Joe Gordon made a pluggable scheduler based on the SimpleScheduler to do the same:
The relevent key here would be 'cs_host_reserved_memory_mb'.

Note that both of these define how much memory goes to your OS and applications, rather than how much memory is set aside for Nova / VMs.  If you had 8GB and wanted to give Nova 6GB, you would reserve 2GB for your host OS.  This is a soft limit, your OS will happily take more memory absent cgroup support as aforementioned.

Eric Windisch

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