Is there anything aone can do to troubleshoot when the Pi hangs so hard it has to be rebooted by pulling the power? This iks a B+ Pi and I intend to solder in a pinheader for the reset switch tonight.
Are you overclocking? If so try disabling.
I had hard hangs because of corruption on SD + external usb HDD’s
No overclocking. As for possible disk problems. That could be an issue. How did you resolve it? fsck?
Edit: It was a hard hang though. Ie the Pi was completely unresponsive. No reply on SSH. Should not the watchdog have caught that?
Edit: I changed /etc/fstab so that the last number on each line is 1 and changed /boot/cmdline.txt, adding fsck.repair=yes and rebooted.
and the result?
Don’t forget to edit fstab again if you have big drives 
Still hangs. Sometimes when playing music, more often when playing video. Fast-forwarding or seeking seems problematic. Can you elaborate on “Don’t forget to edit fstab again if you have big drives”
osmc@pi:~$ sudo cat /boot/cmdline.txt
root=/dev/mmcblk0p2 rootfstype=ext4 rootwait quiet osmcdev=rbp1 fsck.repair=yes
osmc@pi:~$ sudo cat /eyc/fstab
cat: /eyc/fstab: No such file or directory
osmc@pi:~$ sudo cat /etc/fstab
/dev/mmcblk0p1 /boot vfat defaults,noatime 0 1
/dev/mmcblk0p2 / ext4 defaults,noatime 0 1
osmc@pi:~$
Well if you have big drives attached and you let them to be checked on every boot, than booting takes ages. You don’t want 6 terabyte or so to be checked everytime after it hangs (especially if it didn’t solve the problem the first time).
Advised is you enable debugging for logs (most popular answer to problems ;P) so the techies can take a look
True. Large drives will make fsck take a long time. I have an 1Tb external USB for now, but will move data to an external NFS later. Will turn on logging and see what it will reveal. Problem is that hangs are quite random. Might go days when it works without issues, then it just hangs several times one evening.
Edit: Turning on debugging also turns on a rather annoying on-screen display of CPU % and such. I would not mind if it was there when playing music, but it is there when watching TV…