Enable hibernation

[Marc Deslauriers]

On 14-01-06 03:35 PM, Steve Langasek wrote:
> On Fri, Jan 03, 2014 at 05:08:28PM -0500, Phillip Susi wrote:
>> On 1/3/2014 4:50 PM, Steve Langasek wrote:
>>> The hibernate menu option was disabled because it was exposed in
>>> many cases where hibernate would not work reliably.  Indeed, I was
>>> recently trying to
> 
>> According to whom? Is there any record of this testing?  My experience
>> ( and many others ) is that hibernate is more reliable than suspend
>> since it doesn't rely on often buggy bios.  If there is evidence that
>> it is terribly unreliable, I'd like to see it.
> 
> As far back as the Maverick (i.e., 10.10) release notes[1], we prominently
> documented the fact that the hibernate option was not reliable:
> 
>   Hibernation may be unavailable with automatic partitioning. The default
>   partitioning recipe in the installer will in some cases allocate a swap
>   partition that is smaller than the physical memory in the system.  This
>   will prevent the use of hibernation (suspend-to-disk) because the system
>   image will not fit in the swap partition.  If you intend to use
>   hibernation with your system, you should ensure that the swap partition's
>   size is at least as large as the system's physical RAM.  (345126)
>   https://bugs.launchpad.net/ubuntu/+source/partman-auto/+bug/345126
> 
> This was subsequently discussed at UDS, where the decision was taken to drop
> the option from the menu, because despite Colin fixing the recipe, there
> were still other issues with the implementation.  Specifically, I remember
> two main technical problems:
> 
>  - if a newer kernel package has been installed (which happens frequently),
>    resume from hibernation will fail.
>  - if there is insufficient memory, hibernation will fail.
> 
> There was also the design issue:
> 
>  - the difference between suspend and hibernate is opaque to the average
>    user; the user should not have to guess between them.
> 
> It would be nice if we had a ready index for such decisions at past UDSes,
> but unfortunately we don't.

Besides the software and user experience issues above, I seem to recall that the
Canonical OEM testing was uncovering a lot of hardware where hibernation was
unreliable. So much so, in fact, that having it disabled by default and only
enabled once a particular hardware model passed the hibernation stress tests
made sense at that time.

Perhaps firmware has improved since then. Maybe we could get the results of
recent OEM testing and see what percentage of current machines have reliable
hibernation? This would allow us to re-evaluate the decision with some
non-anecdotal facts and would help determine if the software issues are worth
fixing or not.

Marc.