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Re: [Xen-users] IO caching at dom0 level

To: xen-users@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-users] IO caching at dom0 level
From: "Olivier B." <xen.list@xxxxxxxxx>
Date: Mon, 07 Sep 2009 22:35:44 +0200
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Fajar A. Nugraha wrote:
On Mon, Sep 7, 2009 at 11:13 PM, Olivier B.<xen.list@xxxxxxxxx> wrote:
Hi,

is there a way to maintain an IO cache on dom0 for all domU ?

Generally not recommended as it could cause data corruption on domU side.
If you REALLY want to use it anyway despite the consequences, AFAIK
file:/ does that by default, and it should work even for block
devices.
Well if you only do read caching, what problem can you have ?
And for write caching, the problem is the same as for write cache on RAID cards, so barriers should already avoid problems with that, no ?

I will look at your suggestion, thanks.

I have near 1Go not used ram on a Dom0, and would like to use this memory to
speedup all the domU. All my domU use LVM phy devices.

1G is not much :P. IMHO you better add it to the busiest domU.
Well to simulate a "raid hard card", it's enough I think ;)

Olivier

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