[mythtvnz] Long delay when starting playback - possible fix

[Stephen Worthington]

On Sat, 30 Sep 2017 10:50:18 +1300, you wrote:

>A few months ago, I reported a problem where starting to play a recording
>would result in a long pause, around 30 seconds, with the screen completely
>frozen, before the playback would start.  Recently I seem to have stumbled
>on a work-round for the problem.
>
>Every night a script is run, which essentially does this:
>	mysqlcheck -c mythconverg -u root
>If I run the script manually, just before starting the frontend,
>then I don't get the delay on starting to watch a recording.
>
>Looks like maybe a database corruption problem, although it never reports
>finding any errors, just prints an 'OK' for each table checked.
>Any clues from that as to what might be the root cause?

Are you sure that your hard drives are not going into idle?  Many
modern hard drives automatically shut down to save power now, and
MythTV will wait for them to spin up, causing exactly the symptom you
describe.  I have that happen when I have any of my three archive
drives mounted, as I have not disabled the automatic idle mode on
them.  And it always happens when I am playing videos, as two of my
video drives are normally shut down.

To see what state a drive is in, use hdparm -C from a root prompt.
This is the current state of my video storage drives:

root at mypvr:~# hdparm -C /dev/disk/by-label/vid1

/dev/disk/by-label/vid1:
 drive state is:  active/idle
root at mypvr:~# hdparm -C /dev/disk/by-label/vid2

/dev/disk/by-label/vid2:
 drive state is:  standby
root at mypvr:~# hdparm -C /dev/disk/by-label/vid3

/dev/disk/by-label/vid3:
 drive state is:  standby