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On 23/03/15 14:16, Matti Nykyri wrote: |
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>> On Mar 23, 2015, at 14:13, Nikos Chantziaras <realnc@×××××.com> wrote: |
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>> |
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>>> On 23/03/15 11:46, Peter Humphrey wrote: |
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>>> The consensus seems to be that there's no point in trying to prevent a user |
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>>> from rebooting the machine, and I'm happy to go along with that. |
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>>> |
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>>> The remaining question is: why is the user not allowed to halt it? |
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>> |
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>> Because there's no keyboard shortcut for halt. Only for reboot :-) |
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> |
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> Well you can set init to run halt on ctrl-alt-up arrow -keypress. |
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|
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This is mostly about standard expectations though. No one expects to |
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halt the machine with the vulcan pinch. You press the power button for |
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that, which does a safe shutdown in the majority of setups (unless you |
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have all power management features disabled.) |
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|
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Nowadays, only the reset button is a source of evil, as it's not handled |
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by ACPI (or other power management mechanisms). It really is hardwired |
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into resetting the the mainboard/cpu. |
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|
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So: |
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|
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Rebooting with ctrl+alt+del: safe |
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Halting by pressing the machine's power button: safe |
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Pressing the machine's reset button: Ouch! |
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|
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Of course, back in the bad old days, the power button would simply cut |
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power. There was no ACPI or anything equivalent. But still, even then, |
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there was no keyboard shortcut for "halt" anyway, so people weren't |
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expecting to be able to safely halt a machine without root access. The |
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ability to reboot safely, on the other hand, was always expected. |
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