[PLUG] Hibernate problem on Ubuntu 17.04

[Robert Kopp]

Hibernate is not enabled by default on Zesty (or any recent release, for that matter). I have 32GB of RAM, so I created a 35GB swap partition and added it to fstab. I also installed pm-utils and created initramfs-tools/conf.d/resume with RESUME=UUID=xxx and updated with update-initramfs -u.
I tested this with pm-hibernate. The screen went black and there was a message to the effect that something was being written (it appeared very briefly). But it didn't turn of completely, and about a minute later the mouse cursor appeared on an otherwise black screen. (A hard reset was required, and I wasn't surprised that the system state was not preserved.)
So then I tried systemctl hibernate -i. Now it says "Failed to hibernate system via logind: Sleep verb not supported," which is not quite self-explanatory. (I am using an Nvidia GTX 970 display adapter, and there have been some problems reported using these with the hibernate function.) Anyhow, anyone with insight into such matters is encouraged to comment on this issue.