Ubuntu – Ubuntu 18.04 can’t resume after hibernate

18.04hibernate

Hibernate worked correctly when I had been using Ubuntu 17.04. After upgrade to 17.10 I couldn't resume because of black screen after resume (this bug).

After upgrade to 18.04 if I try to start my computer after hibernation it boots as if there was no hibernation done.

Best Answer

There are changes done to default settings when compared to previous LTS (16.04). In my case hibernation didn't work until I've did several steps, among them increased the size of swap file, turned it on, made sure policies allowed it, etc.

This may easily be my lengthiest answer on entire StackExchange so I tried to make headers descriptive.

Boots as there was no hibernation

Would be prudent to take a look at your logs (dmesg might help) and see if anything's there. There are reasons when despite you telling the system to hibernate, it actually won't, or it will suspend-to-RAM instead (sleep).

Taking a look at kern.log and syslog looking for any hibernate-related messages wouldn't hurt as well. Sections starting with "problem" may help you with specific issues.

Swap file or swap partition

One of crucial changes is that now you DO NOT HAVE a swap partition, but you have a swap FILE.

Swap file may not work for your blend of hardware/drivers/OS and hibernation.

Hibernation turned off

Policies may also turn off or disallow hibernation.

Jargon

Suspend to RAM - RAM keeps the data, computer goes to sleep faster, uses more energy when suspended, wakes up faster. Some call this sleep.

Suspend to disk - aka hibernation. RAM is saved to swap (partition or file), computer goes to sleep slower, uses less energy while hibernating, wakes up slower.

Prerequisites - do you have enough space?

To hibernate, you need to (simplification here) save your entire RAM to your hard drive. So, you need to set aside enough space to do so. If you don't, this will fail and you won't hibernate.

free -m will tell you how much memory you have, use and how much is in your swap.
df -h will tell you how much disk space you have on each mount point and how much is used, free, etc. This is important since you may want to later specify where your swap file will be located, or which partition to "trim" to have enough space for your swap.
cat fstab should give you information if you have a swap partition or file. According to Ubuntu Hibernation FAQ swapfile may not always work with some combinations of hardware/drivers.

If you don't have enough space, follow Ubuntu swap FAQ. It tells you how to increase swap file, add another, check if it's used etc. With commands and explanations. Really nice resource.

I don't have enough space to fit my RAM!

Kernel docs say:

/sys/power/image_size controls the size of the image created by the suspend-to-disk mechanism. It can be written a string representing a non-negative integer that will be used as an upper limit of the image size, in bytes. The suspend-to-disk mechanism will do its best to ensure the image size will not exceed that number. However, if this turns out to be impossible, it will try to suspend anyway using the smallest image possible. In particular, if "0" is written to this file, the suspend image will be as small as possible. Reading from this file will display the current image size limit, which is set to 2/5 of available RAM by default.

So, try tweaking your image size. How - ask another question please.

Prerequisites - does your kernel support suspend-to-disk?

Kernel supports whatever is listed in /sys/power/state, so:

cat /sys/power/state

Allowed (to my knowledge) entries there include: mem, standby, freeze, disk. Explanation:

mem - has several meanings, which one exactly on your system you'll find out via cat /sys/power/mem_sleep. I have: s2idle [deep]
standby - Power-On Suspend (if supported)
freeze - Suspend To Idle (STI)
disk - Suspend To Disk (STD), hibernation. This - you want.

Then we need to check cat /sys/power/disk. If you have there disabled then dive in your BIOS looking for Secure Boot - that's the only idea I can offer and only thing I know may interfere and turn off hibernation. While I know only of SecureBoot, there may be other interferences, so taking a look at your BIOS is a good idea even if you don't have there any "secure boot".

Reading here:

TBH, even if your kernel does NOT support hibernation, you can try it in another way, scroll down to section Interfaces.

Read this - warnings and problems - no BTRFS

In no particular order:

Not all chipsets will work (don't have sources that I can cite here so let's say this is hearsay)
VAIO has problems, supposedly there's a flag to counter them
SecureBoot is often cited as interfering or turning off hibernation
Wake-on-LAN consumes power even with hibernation
Number of modules (graphics especially) may be initialized BEFORE your system properly resumes from hibernation - this is usually the cause for black screen when resuming. Look at ArchLinux Wiki for tips on how to debug issues. I'd also suggest Ubuntu FAQ on hibernate issues. Browsing through Launchpad bugs may also yield results. IIRC, there's a kernel parameter specifying in seconds a delay before resume.
Allowing hibernation procedure differs for different Polkit versions

Don't use BTRFS and hibernate: corrupted data will be the result.

I want to hibernate - swap partition

There are cases, when people forego swap file and go back to swap partition. After all, it worked on previous LTS. I did not try, so won't offer pointers.

I want to hibernate - with swap file

Make sure you have enough space there. Ubuntu swap FAQ tells you how much you need, commands from above do so as well. If you need more info here, ask another question please, as this is a lengthy topic.
Increase the swap file or create a new one with good enough size (preferred, I agree with @muru) and change in the /etc/fstab to new one. Reboot to see change is taken well (store backup of the fstab so you can easily revert just in case.
Point your kernel at this with appropriate params, so it know where to resume from.
Update/reconfigure your boot loader and reboot.

Kernel parameters? Scary!

Carefully read and decide if you wish to do that, but it's just a way to configure your kernel. It may be easier to hibernate via systemd and uswsusp (see Interfaces, below). It may be, that you - like me - will ultimately decide suspend-to-RAM is enough and you don't want to have 32GB on a swap file (not so great for folks with one SSD in their laptops, for instance). But!

hibernate to swap file requires resume= to know which partition your swap file is on and resume_offset= to know where in swap file to start resuming from.
hibernate to partition requires resume= to point to swap partition.
resolving black screen issues may well require resumedelay=.

Kernel docs on delaying resuming from Hibernation:

resumedelay= [HIBERNATION] Delay (in seconds) to pause before attempting to read the resume files

Required parameters for swap-file and hibernation:

resume= [SWSUSP]

      Specify the partition device for software suspend

      Format:

      {/dev/<dev> | PARTUUID=<uuid> | <int>:<int> | <hex>}

resume_offset= [SWSUSP]

      Specify the offset from the beginning of the partition
      given by "resume=" at which the swap header is located,
      in <PAGE_SIZE> units (needed only for swap files).

      See Documentation/power/swsusp-and-swap-files.txt

For the resume= choose the same style as root element has in fstab. So, either /dev/sdaX or UUID or LVM. For hibernating to file - provide partition where your file can be found.

Reading:

Problem - swap header not found

Swap file needs to be formatted properly. If your logs tell you this, you either are trying to hibernate to a file, or your resume parameter is not right.

Switch to partition or fix the file or change interface used for hibernation.

See: https://unix.stackexchange.com/questions/43508/debian-hibernate-problem-pm-swap-header-not-found

mkswap is used to format file, read more on it here

Problem! Hibernation not allowed!

Test: pm-hibernate (if pm-utils package is installed) or systemctl hibernate tell you you are not allowed. Default setting in Ubuntu since IIRC 12.04.

Solution(s): depends on your Polkit version, your Ubuntu version and flavour... See this question. Also, ArchWiki on Polkit may help.

For Mint, see: https://forums.linuxmint.com/viewtopic.php?t=259912

Problem! Hibernation disabled by something in BIOS!

Test: cat /sys/power/disk has disabled. Logs show "Failed to hibernate system via logind: Sleep verb not supported".

Solution: search your BIOS and find the problematic thing. Turn it off.

Solution 2: try another hibernate interface.

See: How to activate hibernation in 16.04.1 ? (systemd).

Interfaces

swsusp - low level kernel interface. See Prerequisites - kernel for which files. Writing to files directly may cause suspend (to RAM, to disk and hybrid). According to SwapFAQ problematic with hibernating to file.
uswsusp - ArchWiki and Debian Wiki and nice AskUbuntu question with a write-up how to use it.
systemd - ArchWiki on it
pm-utils - AFAIK that's a collection of scripts originally from Debian - I'll gladly welcome more info myself.

Closing remarks

For me it was a matter of almost two days of work to compile that. Hopefully this will help you (and others) solve your issue faster. There are still points I missed but it's 2 AM and I don't feel like writing more now. I'm of course open to anybody's pointers to make this better, so comment away. I'll reply once I sleep, work etc. :-)

I'm not certain hibernating to disk is that great. I went with sleeping in the end. But for me issue was with having a 32GB file just to be able to do hibernation, since I'm usually avoiding swapping at all. My initial swap-file was at 2GB and it was mostly empty. YMMV. Nevertheless, good luck! And start with the logs!

Update for 16.04 (September, 2016)

Hibernate might not work not even it is successfully enabled if you have btrfs partitions. As revealed in a question here

How can I hibernate on Ubuntu 16.04?

It was also revealed that enabling UEFI can cause problem with hibernation too.

Enable the Hibernate option

To enable Hibernate, I followed this answer from Dima.

After enabling hibernate you will have an option to hibernate in the indicator session menu at top panel. But, though you can hibernate you may not resume from hibernate. You will just be given a new session. The fixes are below.

The fixes to be able to resume from hibernate (12.04)

^{Several readers confirmed this working on 14.04 too}

There is two way to fix this.

1. Editing the `/etc/initramfs-tools/conf.d/resume` file

First get the UUID of the swap partition.
```
 sudo blkid | grep swap
```
This will output a line similar to this:
```
/dev/sda12: UUID="a14f3380-810e-49a7-b42e-72169e66c432" TYPE="swap"
```
The actually line will not match with this. Copy the value of UUID in between "..." double quote.
Open the resume file
```
gksudo gedit /etc/initramfs-tools/conf.d/resume
```
And in that file, add a line like this
```
RESUME=UUID=a14f3380-810e-49a7-b42e-72169e66c432
```
Don't forget to replace the actual UUID value you get from step 1. Save the file and exit gedit
Then in terminal, execute this command
```
sudo update-initramfs -u
```

You will now be able to resume from hibernation

2. Editing the `/etc/default/grub` file.

Open a terminal and execute the below command to open it
```
gksudo gedit /etc/default/grub 
```
There will be a line like GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" . Edit the line to insert RESUME=UUID=<your-uuid-value-here> after the word splash.

For example in my case, the line looks like this after editing
```
 GRUB_CMDLINE_LINUX_DEFAULT="quiet splash resume=UUID=a14f3380-810e-49a7-b42e-72169e66c432" 
```
Make sure, you used your UUID value you get from sudo blkid | grep swap command.
Then do this command
```
 sudo update-grub
```

This also enable you to successfully get resumed from hibernate.

^{Tested on two Ubuntu installation, both worked}

Ubuntu – Cannot resume after hibernate

I had the same issues. There is a bug in the most recent kernel in 16.04. Here are the explicit steps I have done. Do the first one and, if it solves the problem for you, stop there. If not, go on.

1. Set the computer to boot with the previous kernel

Start with:

uname -r

Mine says 4.13... Then do:

grep -i "menuentry '" /boot/grub/grub.cfg

You will see the different menu entries in grub. In my case, together with "Ubuntu, with Linux 4.13..." there was a menu option to boot with the previous kernel. It said Ubuntu, with Linux 4.10.0-28-generic. In the same line you have something like 'gnulinux-4.10.0-28-generic-advanced...(a bunch of caracters here)' Copy that text, and then we have to tell grub2 to boot with that kernel by default:

sudo cp /etc/default/grub /etc/default/grub.back

sudo gedit /etc/default/grub

Then I inserted this line:

GRUB_DEFAULT="gnulinux-advanced-4a50e1e8-56d9-413e-9954-55648888a31d>gnulinux-4.10.0-28-generic-advanced-4a50e1e8-56d9-413e-9954-55648888a31d"

Please do not copy this line literally, but use the output of the previous grep command as said. Then save and,

sudo update-grub

Then re-boot and check that the output of "uname -r" is the older kernel (4.10... in my case). You may be able to hibernate now, or not. If not, proceed to the next step.

2. Install different stuff to hibernate than the default one:

In my case, using the older kernel got rid of the black screen of death and allowed me to resume after hibernation, but the contents of the disk image were going wiped out, i.e. it was identical to a reboot, not hibernation. So I installed some shit that hibernates differently:

sudo apt-get install uswsusp

Then close the terminal, open it again and type:

sudo s2disk

This is supposed to hibernate the computer. If, after resuming, everything is as you left it, then you have solved the issue. But you still need to proceed to step 4 in order to tell Ubuntu that you want to use the new stuff by default and also that you want to have options to hibernate in the applications.

3. Tell grub 2 where the swap partition is:

It still didn't worked for me, so I had to tell grub where the swap partition is:

cat /etc/fstab

I could read there "# swap was on /dev/sda2 during installation", so I edited grub again:

sudo gedit /etc/default/grub

And added:

GRUB_CMDLINE_LINUX_DEFAULT="intel_pstate=disable resume=/dev/sda2"

The important part is "resume=/dev/sda2" but the previous thing (intel blablabla) is there because of other reasons. Well, the next step is:

sudo update-grub

Re-boot and try again to hibernate with some stuff going on (e.g. open a movie with vlc) with:

sudo s2disk

If the stuff is still there after you resume, you have solved the issue.

4. Telling Ubuntu to use the new hibernation stuff you have installed instead of the default:

You have now to tell Ubuntu to use s2disk to hibernate instead of the stuff that comes by default:

sudo gedit /etc/pm/config.d/00sleep_module

And insert there:

SLEEP_MODULE="uswsusp"

Save and close the file. Then:

sudo gedit /etc/polkit-1/localauthority/50-local.d/enable-hibernate.pkla

And insert there:

[Re-enable hibernate by default in upower]

Identity=unix-user:*

Action=org.freedesktop.upower.hibernate

ResultActive=yes

[Re-enable hibernate by default in logind]

Identity=unix-user:*

Action=org.freedesktop.login1.hibernate;org.freedesktop.login1.handle-hibernate-key;org.freedesktop.login1;org.freedesktop.login1.hibernate-multiple-sessions;org.freedesktop.login1.hibernate-ignore-inhibit

ResultActive=yes

Reboot and try again.

5. If after running Step 4, you can't hibernate using sudo systemctl hibernate then do the following

Step 4 is not enough to make the switch to uswsusp in Ubuntu 18.10.

Edit the hibernation service

sudo systemctl edit systemd-hibernate.service

And add the following

[Service]
ExecStart=
ExecStartPre=-/bin/run-parts -v -a pre /usr/lib/systemd/system-sleep
ExecStart=/usr/sbin/s2disk
ExecStartPost=-/bin/run-parts -v --reverse -a post /usr/lib/systemd/system-sleep

Update systemd

sudo systemctl daemon-reload

Test the setup by running the following

sudo systemctl hibernate