MythTV: build or RPM?

[david at thekramers.net (David Kramer)]

Tom Metro wrote:
> David Kramer wrote:
>> I now have FC6 running on my server (instead of SUSE 10.0), and would
>> like to make another go of installing MythTV.  I understand it's a
>> little more difficult when installing it on a server doing a bunch of
>> other things, but that's what I've got.  I can't justify the electricity
>> to run a second computer 24/7.
> 
> So it's not the cost of a second computer, but the electricity that
> concerns you? You might be over estimating the cost of electricity,
> compared to the cost of your time in dealing with the problems you might
> encounter by trying to use one server for everything.

I don't know how I can be overestimating the cost.  Several hundred
watts 24/7 is a lot of electricity.  Would you leave two 150 watt
floodlights on outside your house 24/7 so you can see outside your
window for two hours a night?

> The kind of hardware used for a general mail/firewall type server can be
> quite different from what you want for a MythTV back-end. Will your mail
> server tolerate high CPU usage while videos are being transcoded? Will
> your CPU get loaded from spam filtering and interfere with recording
> video? Do you have a few hundred gigabytes available on your server?

I didn't talk much about my setup because I wasn't anticipating the
conversation going in this direction, but...

I have a PVR-350, so the transcoding/compression/whatever is happening
on the card, and not taking CPU power.  My CPU (an Athlon XP 2400+)
rarely goes below 90% idle, and is usually above 95% idle.  Please
correct me if that won't be good enough.

I also don't plan on watching shows on that box very often.  Most of the
time I'll transfer them to my laptop and watch them there, or more
likely, burn them to DVD-RW and watch them on a TV.  My server is
upstairs in the office, which is generally too hot for my comfort level
(I would keep my house at 68 degrees or cooler if I were the only one
living there, but I'm not), so I don't spend that much time in there.

> If you want to save on power, you might be better off building a
> combined back-end/front-end machine that uses low-power components. You
> could even set it up in a wake-on-LAN mode and have your main server
> wake it up during prime time, if that's when you record shows.

That's a possibility, but that would mean coordinating the programming
schedule pretty tightly between the machines.  But even if I had it
automatically come on at 7PM and shut off at 3PM (I would use X10 not
WOL, but that's me), that wouldn't be too horrible.

But if you don't think my current old-but-somewhat-beefy server is up to
the task, how is some low-energy box going to cut it?  Fast CPU and fast
drives mean bigger power draw.  That's just physics.

I do have a 120GB drive just for data files that has about 100GB free on
it, and if that turns out to be insufficient, I'll add more.  Back when
I first built this box, SATA was still iffy under Linux, but now I hear
it just works great.  My mobo has SATA ports, so I can add SATA drives,
and I have one free IDE port (I have the main drive, the data drive, and
the DVDRWDL drive).

>> The Myth install directories explicitly say, though, if you install
>> things from RPMs that things might work a little differently.
>>
>> So, do you think I should build and install, or use RPMs?
> 
> I can't comment on RPMs, as I went the Ubuntu route, but I'd recommend
> using build packages of some sort, if you can get them. Unless you plan
> to tinker with the code, they'll be less hassle in the long run. I don't

The only meaningful advantage of compiling it myself that I can think of
is that it would be optimized for my CPU.  Other than that, the dozens
of dependencies took forever for me to even get a first crack at being
right when I tried getting it together under SUSE,  It sounds like under
FC6, I add ATRPMs to Yum, then run yum update mythtv-suite (or something
like that), and magical faeries download all the components and
dependencies for me.  Then it's just a few hours of tuning and
configuration to get it happening.  That I can deal with.

> think you'll notice any difference, aside from the usual limitation that
> the packages might lag behind by a revision. Ubuntu seems to have a
> dedicated MythTV community, so they have packages that stay current with
> the latest releases.

I'm really just too busy these days to have the time to worry about
getting it working, I just want it working.  That's why you've seen
several "I'll pay someone to come down and fix this problem for me"
posts in the past year or so.  I would rather grab a bunch of stable,
self-consistent packages than have the ability to grab the CVS code
checked in three hours ago.

I'm still a Tinker/Hacker, but almost exclusively in software
development, not sysadminning these days. Having said that, I'm gonna
post an idea I started working with after I send this email that some of
you might be interested in.

> I started with Dapper (6.06) and noticed the latest MythTV packages were
> only available for the newer Edgy (6.10), so I upgraded to that,
> installed MythTV and video capture drivers (ivtv) from packages. It
> worked, but there were problems with the video capture drivers, which
> supposedly were fixed in the next version. Packages for that version
> were only available for the "bleeding edge" Feisty release of Ubuntu. I
> upgraded to that, updated the packages, and everything worked well.
> Feisty is still rough around the edges, so I wouldn't recommend it for
> general use, but for a machine dedicated to being a MythTV box, it's fine.

Yes, I know it's going to be harder on an integrated box, but I need to
at least try it.  If I find that it doesn't work as well as I need it
to, then I'll build another box and power it down part time as you
suggest.  I might even move my server hard drive over to an Athlon 850 I
have and run Myth on the Athlon XP 2400+ in my server right now.


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