Re: All hash prompts look the same
The -9 is a synonym for KILL. It means the kernel will stop the target process(es) so they never get any more CPU time then deallocate all the process's resources like memory and file descriptors. The meaning of -1 depends on who is asking. If root gives this command it means "all processes except for some special system processes". Anything that is not a "special system process" does not get to put its open files into a consistent state. Expect trouble from any database at the least and probably a bunch of other things too.
If that is not terrifying enough, you then have to guess how special a process has to be so survive. How about the processes that maintain journaled file systems, caches, network and disk access?