I have a headless pi inside an amp and need to run a couple of scripts as soon as the OS is up and as the last thing on power down.
What is the best way to do this ?
The hard way: write your own systemd unit file.
The easy way:
Startup: /etc/rc.local
Shutdown: put your script or symlink in /lib/systemd/system-shutdown/ (fyi that is really right before halting the system. Filesystems e.g. are already read-only when scripts in that directory are called.
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We should add this information to the Wiki
Perfect - thanks !
Thanks casper
I had problem with external hard drive connected to pi suddenly losing power on shutdown which gave a loud click, which didn’t sound good.
Putting hdparm script in system-shutdown folder now powers down drive gracefully on shutdown.
Cheers 
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