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Re: [Xen-devel] Xen Memory De-duplication

To: Xen-devel@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-devel] Xen Memory De-duplication
From: Thomas Goirand <thomas@xxxxxxxxxx>
Date: Tue, 12 Oct 2010 18:20:08 +0800
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Aditya Gadre wrote:
> This kind of implementation will require the disk blocks from
> different DomUs to be mapped to same physical disk block.
> For example,
> 1) Shared read only filesystem
> 2) Union based filesystem
> 3) Virtual machine images deployed on a host filesystem which has
> deduplication enabled
> What kind of  arrangement of filesystem is used in production
> environments for DomUs which host large number of VMs as in cloud
> enviorment?
I don't know for others, but for us (eg: at GPLHost), none of
what you described above is doable. Each VM has its own
LVM partition, and we wont have shared filesystem among
many VMs. Never ever. We don't use virtual machine *images*

What would be nicer, would be a more general approach, and
maybe have the possibility to use a filesystem that is already
mounted on the dom0. Why? Because most of the time, what
is wasted, is the free space in each LVM, in what I described


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