[CentOS] CentOS 7 hibernation laptop

On 06/04/2019 01:01 AM, anax wrote:
> You may try using this page:
>
> https://www.kernel.org/doc/Documentation/power/basic-pm-debugging.txt
>
> suomi
>
> On 03/06/2019 17.54, H wrote:
>> I have a recent Dell Inspiron laptop on which I installed CentOS 7. I have, however, failed somewhere since I do not have a hibernate option when shutting down, only a suspend option. I believe I created the necessary hibernation partition large enough for the RAM the machine has, 16 Gb if I remember correctly.
>>
>> How do I identify where the problem lies?
>>
>> _______________________________________________
>> CentOS mailing list
>> CentOS at centos.org
>> https://lists.centos.org/mailman/listinfo/centos
>>
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Did not have a chance to try the first suggestion on that page until today:

1. Testing hibernation (aka suspend to disk or STD)

To check if hibernation works, you can try to hibernate in the "reboot" mode:

# echo reboot > /sys/power/disk
# echo disk > /sys/power/state

However, even though I am root, the system complains:

-bash: echo: write error: Operation not permitted

Any suggestion on how to find the cause of this message?