Re: Hibernation considerations

[david@lang.hm]

On Mon, 16 Jul 2007, Rafael J. Wysocki wrote:

> On Sunday, 15 July 2007 14:58, Dr. David Alan Gilbert wrote:
> > * Rafael J. Wysocki (rjw@sisk.pl) wrote:
> >
> > > (5) Hibernation should be transparent from the applications' point of view
> > >
> > >     Generally, applications should not notice that hibernation took place.
> > >     [Note that I don't regard all processes as applications and I think that
> > >     there may be processes which need to handle the hibernation in a special
> > >     way.]  Ideally, for example, if some audio is being played when a
> > >     hibernation starts, the audio player should be able to continue playing the
> > >     same audio after the restore from the point in which it has been
> > >     interrupted by the hibernation.  Also, the CPU affinities and similar
> >
> > That would be _so_ embarrassing in a library; I'd rather the audio
> > player had the opportunity to consider whether restarting was a good idea.
> >
> > > (6) State of devices from before hibernation should be restored, if possible
> > >
> > >     If possible, during a restore devices should be brought back to the same
> > >     state in which they were before the corresponding hibernation.  Of course
> > >     in some situations it might be impossible to do that (eg. the user
> > >     connected the hibernated system to a different IP subnet and then
> > >     restored), but as a general rule, we should do our best to restore the
> > >     state of devices, which is directly related to point (5) above.
> >
> > Or the user unplugs their flash drive after hibernation rather than before.
> >
> > Two things which I think would be nice to consider are:
> >    1) Encryption - I'd actually prefer if my luks device did not
> >        remember the key accross a hibernation; I want to be forced to
> >        reenter the phrase.  However I don't know what the best thing
> >        to do to partitions/applications using the luks device is.
>
> Encryption is possible with both the userland hibernation (aka uswsusp) and
> TuxOnIce (formerly known as suspend2).  Still, I don't consider it as a "must
> have" feature for a framework to be generally useful (many users don't use it
> anyway).

he's talking about the main system useing an encrypted device/partition, 
not the hibernate image being stored encrypted.

This would require the main system 'forget' the keys when it does the 
hinbernate and prompt for it again during the wake-up phase.

David Lang

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