[mythtv-users] backends without tuners (was Re: Transcoding is being done on frontends, not backend)
Michael T. Dean
mtdean at thirdcontact.com
Fri Jan 9 17:29:49 UTC 2009
On 01/08/2009 11:05 PM, Craig Sanders wrote:
> On Thu, Jan 08, 2009 at 03:47:03PM -0800, Brad DerManouelian wrote:
>> The supported method of running jobs on other machines that do not
>> have tuners is to run mythjobqueue.
> the only mention of mythjobqueue in the manual is a few paragraphs at
> section 23.25 - there's no mention anywhere in the manual that tunerless
> backends are unsupported, or that mythjobqueue should be used instead of
> mythbackend if no tuners are installed.
Note that if you run mythbackend on a host without any configured
capture cards, all the parts of mythbackend that are not included in
mythjobqueue are disabled--meaning you're basically running mythjobqueue
+ cruft. "What cruft?" you may ask.
# pmap -d `pidof mythbackend`
1683: mythbackend -d -l /home/mythtv/log/mythtv.log
mapped: 335940K writeable/private: 287712K shared: 0K
# pmap -d `pidof mythjobqueue`
mapped: 144584K writeable/private: 35284K shared: 0K
So that's 252428KiB of cruft (287712K - 35284K). (Using
writeable/private as mapped includes shared libraries like the MythTV
libs (and many others) that are already in use by other apps--such as
Yeah, I realize that 256MiB of RAM isn't too expensive today, but why
fill it up with garbage you're not using? Why not use it for something
useful, like the kernel buffers/cache--or preventing mythtranscode or
mythcommflag from hitting swap or ...
And, as Brad has mentioned, since it was designed to be used that way,
it's been tested that way.
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