rasPi Stretch Lite install notes

[Achim Gratz]

Hal Murray via devel writes:
> I keep daily log files.  I think I modified the start script to copy the 
> latest day to the tempfs and the stop script would copy it back and an hourly 
> cron job would also copy it back and delete older files.

Yes, quite siomilar to what I had in mind, but I'd probably run a
background process to write each block as it becomes full and maybe
pre-allocate the preferred block size of the SD card off the end of the
file.

> It would be worth doing the arithmetic to see how long a SD card should last 
> at normal logging rates.

There are too many variables to know that.  The failed card had
roundabout 1GB of data written to it for the logs, plus about one OS
update per week, which probably means on the order of 10…40GB more
traffic on the card.  Even very conservatively estimated it should be
good for getting over 240GB of data written to it and probably closer to
1TB so either the write amplification was rather large or the
wear-leveling on that card was not prepared for that sort of write
pattern.

> The logging code currently includes a flush.  A few lines of code could batch 
> that.

Unless it's made optional it should be kept that way.


Regards,
Achim.
-- 
+<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+

SD adaptations for Waldorf Q V3.00R3 and Q+ V3.54R2:
http://Synth.Stromeko.net/Downloads.html#WaldorfSDada