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Re: [Xen-devel] Re: how to change the memory size of a VM

To: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] Re: how to change the memory size of a VM
From: Jia Rao <rickenrao@xxxxxxxxx>
Date: Mon, 2 Nov 2009 16:46:23 -0500
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What I understand here is:

Although configured with 2GB memory, the guest only used part of the assigned memory(active onees), gives the unused memory back to xen.
Upon reconfigured to 1GB, the guest got informed from xenstore about the new size, and updates its own view of the memory info, like the number in /proc/meminfo.

Is it correct ?

On Mon, Nov 2, 2009 at 4:37 PM, Keir Fraser <keir.fraser@xxxxxxxxxxxxx> wrote:
On 02/11/2009 20:54, "Jia Rao" <rickenrao@xxxxxxxxx> wrote:

> It seems that to change the memory size of a VM, you just need to save the new
> size in somewhere, xenstore?
> How would the new size take effect? the memory mapping of the VM must be
> modified somewhere.

The VM itself gives up memory back to Xen, after reading the updated memory
size from xenstore.

 -- Keir

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