Comment 7 for bug 223770

hyperair - gnome-power-manager doesn't invoke pm-is-supported. g-p-m gets the power capabilities over HAL, which gets them from pm-utils. HAL only checks the capabilities when it starts I think.

Thinking about it, I'm not sure this is such a good idea. The used RAM is compressed before being written to swap when you hibernate, so I think it is difficult to predict exactly how much disk space is required for hibernation. I wouldn't want my machine to suddenly decide to disable hibernate on the off-chance that the image might not fit on disk. I would rather it tried to hibernate, and then failed gracefully if there was not enough disk space to hibernate. In this situation, the user should then be presented with a message telling them why hibernate failed (which doesn't happen currently, and there is already a bug report for that somewhere).

And I think that it would be even more confusing to users if they find that hibernate keeps disappearing and reappearing in their session dialog or fast user switch applet of whatever they use, for seemingly no apparent reason.