Tips and tricks: When I shut down a guest domain under Xen, Domain 0 does not reclaim the memory. Why is this?

Contributed by Chris Lalancette and Eduardo Damato

Release Found: Red Hat Enterprise Linux 5

The idea with Domain 0 is that it is a minimal system that doesn’t have a lot of services on it. The main thing it is supposed to do is start, stop, and otherwise manage domains that do the real work on the system. When a domain shuts down, Domain 0 doesn’t actually reclaim the memory since it is expecting to start another guest domain in that memory. Therefore, it doesn’t waste time reclaiming memory which would be required next time. If a user wants to force Domain 0 to reclaim all of memory, use the command:

# virsh setmem 0 <memory-size>

or :

# xm mem-set 0 <memory-size>

where <memory-size> is the total amount of memory in the host system.

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This entry was posted by the editorial team on Monday, September 10th, 2007 at 7:39 am and is filed under Red Hat Enterprise Linux, tips and tricks. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.