[mythtv-users] Delete files slowly

Greg Oliver oliver.greg at gmail.com
Wed Feb 3 16:50:24 UTC 2010

On Tue, Feb 2, 2010 at 9:48 PM, Michael T. Dean <mtdean at thirdcontact.com> wrote:
> On 01/26/2010 12:31 AM, Michael T. Dean 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..
>> 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.
> While it sounds like this may have been an ephemeral issue caused by
> something else writing to the disk drive, I did bump up the truncate
> speed as well as restore the minimum truncate rate in trunk [23435].
> This means that if you have 1 or 2 capture cards defined in your system
> (where number of cards includes "virtual" cards used for multirec), your
> system will truncate at 8MiB/sec (or about 2min 8sec per GiB), and 3 or
> more cards will truncate at even higher rates (proportional to the
> number of cards).  Before the change, a system with only one capture
> card would have truncated at a rate of about 7min 24sec per GiB.
> So, this change should add a bit more overheard both for systems with
> many cards and for systems with only one or two cards.  Therefore, it
> should even handle cases where the commflagger or transcoder or frontend
> or whatever is spewing out a ton of log messages from libav* complaining
> about the video or whatever.
> Granted, if you have other non-Myth processes writing to the same disk,
> you can still out-write the truncates, so we still recommend having
> recordings directories on separate file systems not used by other apps.
> Anyway, thanks for the report, and please let me know if you see any
> other issues.

OK - will do.  Problem is I think someone else may have been copying
ISOs to the machine.  That's all I can think of.  It has not happened
again, and since I am only using this revo test bed still (and the
drive is puny) - I would have to say it works as advertised.  I have
not lost any recordings, and it is auto-deleting all the time.



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