[mythtv-users] Disk activity at end of recording

[Mark Kundinger]

I also get the recoding-stopping stutter, on a JFS partition, watching
non-HD content that only uses 15-20% cpu.  I had thought it was
transcoding or commflaggin starting, but since you don't see that, it
must just be come voodoo recording completion stuff.

I am pretty sure (not 100%) that the ringbuffer only refers to watching
Live TV, not recordings.



--- Jack Perveiler <perveilerj at yahoo.com> wrote:

> Hello,
> 
> When recordings stop (the recording... not playing back a recording)
> I get a
> flurry of disk activity for a second or two... usually enough to
> cause a
> stutter for a second if I'm watching a HD recording at the same time.
>  So if
> I'm watching a HD recording I can pretty much count on some jitter
> every half
> hour as recordings finish.
> 
> Some info about my system:
> 
> 0) P4 3.0 GHz w/Hyperthreading (HD playback consumes about 70%
> processor)
> 1) Tuners are HD-3000 and PVR-500 (usually the HD-3000 and one of the
> 500
> tuners is recording)
> 2) File system is 200 GB XFS LVM local to the machine (combination
> frontend/backend).  DMA is on (UDMA5).  Output from hdparm:
> /dev/hda:
>  multcount    = 16 (on)
>  IO_support   =  1 (32-bit)
>  unmaskirq    =  1 (on)
>  using_dma    =  1 (on)
>  keepsettings =  0 (off)
>  readonly     =  0 (off)
>  readahead    = 256 (on)
>  geometry     = 30515/255/63, sectors = 490234752, start = 0
> 
> 3) No transcoding or commflagging is going on (they're restricted to
> when I'm
> sleeping).
> 
> So now for my questions:
> 
> 1) Does myth do some sort of minimal post-processing when a recording
> finishes?
>  Or is this just the OS flushing the remainder of the buffer to disk
> and
> closing the file?  Is this maybe something that XFS is just slow at?
> 
> 2) I see in one of the frontend setup pages you can set the size of a
> HD buffer
> to help "weather backend storms" (or something like that).  Is this
> one of
> those cases?  If not, what exactly is that setting for?
> 
> Thanks,
> 
> --Jack