<br><br><div class="gmail_quote">On 20 July 2010 23:20, Simon Hobson <span dir="ltr"><<a href="mailto:linux@thehobsons.co.uk">linux@thehobsons.co.uk</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
Tyler T wrote:<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="im">
I tried to do PCI passthough in Xen a couple years ago and remember<br></div>
lots of pain, perhaps it's better now ...<br>
</blockquote>
<br>
I'm running a backend as a VM with PCI passthrough. I don't seem to remember having had any problems with that - and it's not exactly what you'd call up to date versions either. I actually do passthrough for two cards - one tuner for the Myth backend, and a network card for my firewall/gateway.<div class="im">
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<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
One more thought: I believe SiliconDust sells a DVB version of the HD<br>
HomeRun. If you go that route, a Gig-E NIC in your server should be<br>
able to handle 6+ tuners no sweat, and no mucking about with USB<br>
drivers.<br>
</blockquote>
<br></div>
However, you may hit another issue with Xen - network performance. AIUI the networking in Xen is single threaded, and so if your guests are hard on the network then performance can suffer. For that reason, using iSCSI in a guest sucks performance wise - but it's OK if you do the iSCSI in Dom0 and pass the result block device through as a virtual block device to the DomU.<br>
<br>
As a reference point, I run a single AMD64-2000 processor, 4G ram, a single 1.5TB WD Green drive, and a number of guests (mostly fairly lightly loaded). I've a single HVR 1110 PCI DVB tuner setup with 3 virtual tuners in MythTV. It will happily record two programs while I watch another, it seems to be just over the limit to record 3 while I watch one, and it definitely can't commflag a recording while recording two and watching another - I rather suspect I'm hitting the disk I/O limit of the single drive.<br>
<br>
On the whole, I reckon that you are likely to hit disk I/O limits long before you hit the Dom0 network bottleneck.<br>
<br>
At some point I'll be looking to upgrade and I've been thinking about how to arrange things. I could just do what I've got now, but with better hardware; or I'd considered running Myth on Dom0 and the rest as they are now.<br>
</blockquote><div><br></div><div><br></div><div>Is Xen still the best solution? with RH not supporting it any longer and kvm seemingly taking over?</div><div><br></div><div>Does HD Homerun come in a dvb-t and dvb-s2 varient? I am in a non dvb-c area of the UK.</div>
<div><br></div><div>Anyone know if kvm or virtualbox (is it a rubbish solution to this problem?) have the same network issues?</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<font color="#888888">
<br>
-- <br>
Simon Hobson<br>
<br>
Visit <a href="http://www.magpiesnestpublishing.co.uk/" target="_blank">http://www.magpiesnestpublishing.co.uk/</a> for books by acclaimed<br>
author Gladys Hobson. Novels - poetry - short stories - ideal as<br>
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