[mythtv-users] Delete files slowly

[Greg Oliver]

On Tue, Jan 26, 2010 at 7:31 AM, Greg Oliver <oliver.greg at gmail.com> wrote:
> On Mon, Jan 25, 2010 at 11:31 PM, Michael T. Dean
> <mtdean at thirdcontact.com> wrote:
>> On 01/25/2010 08:32 PM, Greg Oliver wrote:
>>> I just noticed that while I have the setting to delete files slowly,
>>> and recording, it records faster than it deletes.
>>>
>>> Is there logic in this setting, or can I assume that it will always
>>> delete slower than 19mb/s (1 tuner)..  I guess ultimately I would hate
>>> to have frame loss because it is clearing disk space too slowly, but I
>>> am not familiar with the logic.  It may very well delete much faster
>>> as the available space gets lower, etc..
>>>
>>
>> Greg,
>>
>> It turns out that we used to have a minimum truncate rate of 8MiB/sec
>> and would use that value or 120% the max recording bitrate (combined max
>> bitrate of all cards), whichever was higher.  Before 0.21 was released,
>> we removed the minimum truncate rate, so now do 120% ATSC max bitrate *
>> number of cards (basically 2.78MiB/sec/card (including "virtual" cards
>> for multirec)).
>>
>> After some discussion on IRC, we may re-institute the minimum truncate
>> rate.  I plan to do some tests using different values for the truncate
>> rate (from the above 2.78MiB/sec (for the "minimal" one-card system) to
>> 4MiB/sec to 8MiB/sec) and see if it has an effect on
>> http://svn.mythtv.org/trac/ticket/7315 (per discussion at and after
>> http://www.gossamer-threads.com/lists/mythtv/dev/416521#416521 ).  If
>> any of the values "fixes" #7315, I'll definitely institute a hard floor
>> higher than the current.
>
> Well, since my "proof of concept" machine is kind of puny (revo 1600),
> using the entire disk for /, and 1gB for /home - could that play into
> it as well.  I only have recurring recordings set for Monday nights
> (24, heroes, house, etc...) to test things.  BUT - I have also copied
> a few of my ripped DVDs to it as well.  (Never restarting the BE/FE
> combo)..
>
>> I won't be home until later this week, but if any enterprising users
>> want to run some tests for me, please feel free.  You can simply
>> hard-code values for min_tps at
>> http://svn.mythtv.org/trac/browser/trunk/mythtv/programs/mythbackend/mainserver.cpp#L1915
>> , i.e.:
>
> I've been a happy *buntu user (until now) for a couple of years.  My
> new job (moved from networking to systems) made it a pain to work on
> my own machines fulltime, so I went the easy route.  I think I am
> going to have to go back to gentoo for mythtv though...
>
>> const size_t min_tps = 1024 * 1024 * 8;
>>
>> Also, do you have any stats showing the record rate and the delete
>> rate?  Are you sure some other process (or maybe MythTV log files)
>> wasn't what caused the disk usage to increase faster than free space?
>> If so, those stats (and any info you may have on why the 120% ATSC max
>> bitrate * number of cards didn't work for you) would be very useful.

OK, so last night, I had dd working in the background creating files
with the lowest nice priority, while I was recording from 2 tuners
from an hdhr.  I never had a hiccup.  I'm not sure what triggered this
the previous night.  The only thing I did was copy .iso(s) ripped with
mtd from a long running .19 installation over to this new test box.

-Greg