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So what ever happened to hybrid suspend, where it would suspend to both RAM and disk? It was kind of hot a few years ago, but it seems it was dropped. Is there any way to set this up in recent Ubuntu versions?

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What's the point of hybrid suspend?? – Source Lab Aug 8 '10 at 22:38
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Hybrid suspend is when your computer does suspend-to-disk and suspend-to-RAM at the same time. So you get the fast resume speed of suspend-to-RAM, but you don't lose your session if you lose power or run out of battery. So in principle, it's better than either suspend-to-ram or suspend-to-disk alone. Which is why I'm wondering why it seems to have disappeared from the feature lists of modern Linux distros. – Ryan Thompson Aug 9 '10 at 4:46
In the "On Battery Power" tab in the power manager I see an option to "When battery power is critically low: Hibernate", perhaps that removes the need for a hybrid suspend? – Jorge Castro Aug 9 '10 at 21:23
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+1 for using the word "whither" ;-) – Rob Cowell Aug 10 '10 at 9:54
@Jorge: Another use case is if you need to remove your laptop battery (or unplug your suspended desktop PC) for some reason. If you're in hybrid suspend, it won't matter. If you're in regular suspend-to-RAM, you'd have to resume and then suspend to disk. – Ryan Thompson Aug 10 '10 at 17:56

2 Answers

up vote 7 down vote accepted

There is a program called pm-is-supported that can be used to check for the suspend capabilities of the system.

On my system here are the results (0 means supported, 1 means unsupported):

$ pm-is-supported --suspend ; echo $?  
0  
$ pm-is-supported --hibernate ; echo $?
0
$ pm-is-supported --suspend-hybrid ; echo $?
1

The manpage of pm-is-supported suggests that s2both supports hybrid suspend. I've installed s2both, available in the uswsusp package but it still reports that hybrid suspend is not supported. I have a hunch that it needs a reboot because it updated the initrd image. I'm gonna reboot and report back. Wish me luck.

Update: Running sudo s2both wrote the snapshot to disk and suspended to RAM correctly, however when I pressed a key to resume the system rebooted (and didn't restore the snapshot from disk).

I think there's something wrong with the uswsusp package in ubuntu. The splashy package (which is used by uswsusp) has a file conflict with lsb-base which has been left unfixed since Jaunty ( https://bugs.launchpad.net/ubuntu/+source/splashy/+bug/328089 )

Try running sudo s2both or sudo pm-suspend-hybrid, see if it works on your system.

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I tried s2both and got the same results as you. I also tried switching to a tuxonice kernel and telling pm-utils to use tuxonice, and then using the tuxonice hybrid suspend via pm-suspend-hybrid. The screen never turned on when I resumed, but Control+Alt+Delete worked to reboot, so I think it actually worked, but failed to turn on the screen. – Ryan Thompson Aug 10 '10 at 17:54
I guess it's not supported. – Ryan Thompson Oct 10 '10 at 21:05
up vote 1 down vote

You can enable hybrid suspend by following the answer to this question:

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