[mythtv-users] Shutdown unused slaves

[Bob]

Nick wrote:
> On 20/03/06, Bob <spam at homeurl.co.uk> wrote:
>> I had wanted the FE/BEs to shutdown automatically when not in use and
>> have the master BE WOL them when they were needed for a recording or to
>> help out when the transcoding or commflaging queue got too long.
>>
>> Is this really not possible? What would need doing to make this work?
> 
> I'd would guess that the slave FE/BEs would need to poll the upcoming
> recording scheudule, and if one of the slaves was not going to be
> required for a certain amount of time, could then run its own shutdown
> script.

Yes, though I was hoping to take it one stage further and have it not 
only look at upcoming recordings but also at any pending transcode or 
comflagging jobs and only have it shut down when it had nothing to do, 
then I could use some low power VIA MBE and have my SBE/FEs step in to 
help with the heavy lifting.

> The MBE could then use WOL to wakeup the slave(s) when it was
> needed.

Yes but again not just for recording but also if the trans/flagging 
queue is longer that x, you could probably get round this by not having 
a capture source in the MBE, then whenever a trans/flagging job is 
pending there'll be a SBE on having just recorded it.  The SBE shutdown 
script could have a look and if there were more than say 4 jobs in the 
queue, do one and then have another look, alternatively you could set 
the threshold to 1 job, disable any trans/flagging on the MBE and then 
it'd have the grunt to run asterisk, samba and some other useful stuff [1].

> This could be very useful if the MBE scheduler added new recordings
> for the SBE machines to record as WOL could wake them up at the new
> time, whereas a SDWU script using nvram-wakeup or similar would not as
> the wakeup time is hard-coded in the BIOS. It's certainly a feature I
> look forward to.

I thought MythTV already used WOL to power up SBEs when needed for a 
recording, as for the rest, I have no idea how hard such features would 
be to implement, or if they're planed, do you?

[1] I know it could probably do this anyway but it's a 800Mhz Samuel 2, 
really it couldn't pull the skin of a rice pudding. Memtest reports a 
giddy 106MB/s of memory bandwidth.