Many times I’ve gone to hit CTRL-K, S in a JOE session to save changes to a file but missed the “K” meaning I actually sent CTRL-S to the terminal which sends a “stop flow” signal.
Both my network monitoring servers suffered this condition over the 2wks my company takes holidays for Christmas so I returned to work to find 2 VMs consuming 6ghz of CPU between them. A quick check of top showed mysqld_safe consuming 100% CPU on both VMs for no apparent reason.
I extracted a tarball which had applied 777 (rwx) permissions to all files and directories that it contained. I wanted to set all files to 644 and all directories to 755, but there were too many levels to do it manually so I needed to do it through a shell script.