"Perry E. Metzger" <perry@piermont.com> writes:

> The way I'd manage this, I'd lock out userland, flush all dirty
> buffers (both so there is no problem with the file system later if
> one fails to wake up and to reduce the amount one needs to write
> out), nuke all text pages you can demand page in later, etc.

There are devices that it is better to actively passify by calling
driver hookers and the networking stack to consider in this.

> Once your system is pretty quiescent, you probably need to write out
> the system state quite carefully, as you note. That's probably where
> all the ingenuity has to go in.

Writing and restoring state turns out to be the easy part, if you'd
gotten the hard part done. it's just a byte-copy to storage, after all
;)