Why would anyone want to "halt" their machine and not "poweroff"?

MelvynDrag

After running "shutdown --halt now" on an Ubuntu 18 machine, the computer shows a splash screen showing that its stopping everything, closing sockets, etc.., but then it stays powered on. Why would anyone want the thing to stay powered on? Seems that to get it back in a useable state you have to power it off and on anyway, so why is there even an option to not power off?

k0dard

Hello MelvynDrag,

Someone correct me if I'm wrong, but if I remember well halt was used for machines that hadpower switches, like ON/OFF position, and hence couldn't be switched off automatically

luisviveropena

Hi @k0dard, that's right. So in the old times some hardware had to be powered off with a switch. So you needed to be sure when you had to push the button (once that the OS was shutdown), so 'halt' was used for that purpose.

Regards,
Luis.

lee42x

We use halt in our High Availably systems. If a node was declared dead by the monitor and it popped back to life it was halted. This was done to protect the shared file systems that were shared only in connection not multi host file systems.