powerdown restarts

[Bill Davidsen]

Paweł Brodacki wrote:
> 2012/7/2 Richard Vickery <richard.vickeryrv at gmail.com>:
>> On Mon, Jul 2, 2012 at 11:14 AM, Joe Zeff <joe at zeff.us> wrote:
>> How do we boot up after "halt" or "sleep"? I quit using these commands years
>> ago for lack of knowledge about booting back up. The man pages never gave me
>> what I needed to know, and now that it has been brought up, I thought that I
>> would ask and get my curiosity satisfied.
>>
>> Thanks.
>>
>
> I'm not using "sleep", but "halt" (stop the system, leave it powered
> up) is very handy for systems with an UPS. On prolonged power loss UPS
> will tell the system to halt, then wait a bit to give it time, then
> cut the power. When sweet electricity starts flowing from the socket
> in the wall once again, UPS gives power back to the system, which then
> restores itself to the last power state, i.e. powered up. This results
> in a nice boot and the machine is alive and kicking once again.
>
> If the system was shut down, then it would just remain shut down after
> power was restored.
>
Depending on the behavior options in both the UPS and BIOS, you can do many 
things to suit your needs. My power is rarely off for long, so I prefer to stay 
up for a while. If I lose net connection (ISP dropped) I change the spin down 
time on data drives to a lower value, root and swap are on ssd, and CPU speed is 
already set to drop to slow without low.

A custom script can help give you the policy you need.

Sounds as if you are just doing a clean shutdown, and for many people that's the 
important thing, have the system do the best thing for your own needs.


-- 
Bill Davidsen <davidsen at tmr.com>
   "We have more to fear from the bungling of the incompetent than from
the machinations of the wicked."  - from Slashdot