[TUHS] reboot(2) system call

Dave Horsfall dave at horsfall.org
Sun Jan 31 08:27:10 AEST 2021

On Tue, 26 Jan 2021, Greg A. Woods wrote:

> The lore I was told at the time was that you alwasy ran three and that 
> it didn't matter if they were all on the same line with semicolons or 
> not because of the very fact that the second one would block.

What I was taught was:

 	% sync
 	% sync
 	% sync

and never:

 	% sync; sync; sync

The theory was that by waiting for the shell prompt each time, it gave the 
buffer pool enough time to be flushed.

> The third one was just for superstitious good luck, and just in case 
> there was a process still running and writing to a filesystem.

Never heard that theory, but naturally you did a "ps ax" first, didn't 

-- Dave

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