On Fri, Nov 13, 2020 at 11:10 PM Samuel Sieb <samuel(a)sieb.net> wrote:
On 11/13/20 9:39 PM, Tim via users wrote:
> On Fri, 2020-11-13 at 21:24 +0530, Sreyan Chakravarty wrote:
>> I have no idea why this is happening when I have 8GB of free swap space :
>>
>> $ free -h
>> total used free shared buff/cache
available
>> Mem: 7.7Gi 1.6Gi 4.1Gi 269Mi 2.0Gi 5.6Gi
>> Swap: 8.0Gi 0B 8.0Gi
>>
>> My RAM is also 8GB.
>
> The old recommendation always was to have *MORE* swap space than RAM.
That's a good point. The memory usage is quite low at that point, but
if he ever ended up using swap space, there could easily not be enough
to hibernate. However, it should work in this current case.
Hibernation is pretty complicated. What should happen is the kernel
evicts dirty pages to swap in order to free up 50% RAM. Then the
kernel uses that free memory to create the hibernation image and
compress it and then it gets written into swap. So there are some
opportunities for it to fail.
There's a bunch of tests to do to help narrow down the problem.
https://www.kernel.org/doc/html/latest/power/basic-pm-debugging.html
Note that swapfiles on Btrfs additionally need an offset boot parameter added.
https://bugzilla.kernel.org/show_bug.cgi?id=202803#c9
--
Chris Murphy