[mythtv-users] Back-end Virtualization

[Simon Hobson]

Nathan Hawkins wrote:

>Is 'Anyone' virtualizing their backend?! I cant 
>believe I'm the only person out there who wants 
>to do thisŠ If you are using a VMŠplease explain 
>how ya have things setup.

I used to, but now I have dedicated hardware.

My first foray into MythTV was to run up a Xen PV 
guest on my existing server - AMD64 3200+, 4G 
RAM, single disk. Did PCI passthrough for a 
single DVB-T tuner (HVR 1200 or 1250, something 
like that, it's been a while now). Storage was as 
"just another LVM volume" on the host.

As you can imagine, this had significant 
constraints ! It certainly worked, I could record 
2 programs while watching something else as long 
as I didn't commflag and there'd still be hiccups 
when "other stuff" (such as my internal mail 
server) on the machine got busy. I have to add 
that during much of this time, we were pre-DSO*, 
and we had an old aerial on old cable, so calm 
summer evenings we'd lose one or two muxes 
altogether for an hour or so either side of 
sunset - and it was sometimes difficult to decide 
whether it was my setup of the poor signal at 
fault for bad recordings.
But it worked, I ran it for some years, and my 
only investment to get it going was the tuner 
card. Making allowances for the resources I 
didn't give it, I was very happy with it.

* DSO = Digital Switch Over. Over in the UK we've 
been going through a process of switching from 
analogue to digital. Initially the digital muxes 
were transmitted as quite low power so as not to 
interfere with the analogue channels - leading to 
lots of problems if the aerial was anything at 
all lacking in performance.

Fast forward to last year.
HP had a cashback offer on their Microservers - 
at the time, N31L AMD64 dual core, low power, 
room for four SATA drives. With cashback, these 
were £140. My plan was to run one box, Xen, and 
have MythTV as a PV guest again (but with 
dedicated space for storage). However, I found 
that with anything above 4GB or RAM in the 
system, the HVR1300 tuner card didn't work 
properly.
As the cashback offer was still on, and with the 
low power two of these would still use less than 
my old box, I bought a second - one runs MythTV 
backend, the other runs everything else.

Had I been using an external tuner (such as the 
HD HomeRun which now has a DVB-T version) then I 
might well have ended up with the backend as a 
guest under Xen.

-- 
Simon Hobson

Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed
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