What would be the best way to have a computer turns on instantly after the car starts up?
I was thinking I could run my computer off the car battery and when the car shuts off, I would suspend the computer and run it off the car battery and when it starts back up I would resume the operation.
The only thing I see with this is it will fully drain my car battery so I was thinking about getting an additional battery to run it off of while the car was shutdown.
It's for a client they need instant on functionality. So please don't ask me why, but I do.
i believe the opus psu has the ability to keep the 5v rail on, that'll make it possible for you the suspend. I think most battery are able to hold the 5v running for a few days *no garantee on that*. Otherwise a laptop is your best best.
One option that might be available to you is hybrid suspend mode. When you suspend your computer in hybrid suspend mode, it will save a suspend-to-disk hibernate file, but will enter S3 suspend mode rather than fully powering off. This provides two options for resuming:
- If power is maintained to your system the whole time, it will remain sleeping in S3 suspend mode, and will resume quickly
- If the power is cut, your system will resume from the hibernate image, which takes longer but has the same result
On top of this, if your power supply supports it, you can configure it to leave power to your system for some amount of time, and if you don't start the car after, say, 24 hours, have it cut power to the system to save your battery.
If you actually intended to post in the Linux forums, there is documentation out there to configure Linux to boot in less than 5 seconds from a cold boot.