sedf oversubscription

sedf oversubscription

[Diwaker Gupta]

I looked around but haven't found a definitive answer to this on the
mailing list archives -- how does SEDF handle oversubscription? I'm
not using weights at all -- just period/slice specifications for each
domain. So what happens if a user tries to give a specification where
sum(period/slice over all domains) > 1?

Looking at the code it seems that SEDF just *assumes* that the
specification will be valid. Is that correct? Does anyone have a
handle on how the scheduler will behave if an invalid spec is given? I
guess I could just try for myself....

-- 
Web/Blog/Gallery: http://floatingsun.net

Multiple I/O domains?

[Rob Gardner]

I'd like to set up a xen system with mutliple I/O domains.

A few questions:

Is this known to work?

Should I use xen 2.0x or xen 3.x to start with. Which has better support 
for multiple I/O domains?

Is there a cookbook someplace for doing this? A quick search didn't 
reveal anything. A few people have already given us some hints, but the 
information is a little too sparse.

Finally, are there some requirements that aren't obvious? For instance, 
I've got a machine with with one disk and one nic. Is that sufficient, 
or do I need additional interfaces? I'd like to be able to have just two 
domains, one controlling the nic, the other disk. Is this possible? It 
seems like dom0 must be the driver domain for its own boot device.

Rob Gardner

RE: Multiple I/O domains?

[Neugebauer, Rolf]

Multiple IO domains are currently not supported in 3.x. this is mainly
due to the moving of the PCI into dom0 (out of Xen). There was a
discussion on this a month back on the mailing list on how to re-enable
this, but I don't know if anyone is actively working on this at the
moment.

If you want multiple io domains you'd have to use 2.x for now. There is
a xen command option allowing you to hide pci devices from dom0 and then
the config file for a VM has an option to assign a PCI device to another
VM. AFAIK there is no cookbook for this

rolf

> -----Original Message-----
> From: xen-devel-bounces@lists.xensource.com [mailto:xen-devel-
> bounces@lists.xensource.com] On Behalf Of Rob Gardner
> Sent: 31 August 2005 22:54
> Cc: xen-devel@lists.xensource.com
> Subject: [Xen-devel] Multiple I/O domains?
> 
> I'd like to set up a xen system with mutliple I/O domains.
> 
> A few questions:
> 
> Is this known to work?
> 
> Should I use xen 2.0x or xen 3.x to start with. Which has better
support
> for multiple I/O domains?
> 
> Is there a cookbook someplace for doing this? A quick search didn't
> reveal anything. A few people have already given us some hints, but
the
> information is a little too sparse.
> 
> Finally, are there some requirements that aren't obvious? For
instance,
> I've got a machine with with one disk and one nic. Is that sufficient,
> or do I need additional interfaces? I'd like to be able to have just
two
> domains, one controlling the nic, the other disk. Is this possible? It
> seems like dom0 must be the driver domain for its own boot device.
> 
> Rob Gardner
> 
> 
> 
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