Elogind

elogind is extracted out of "logind" - systemd login manager to be a standalone daemon and provides Seat manager support by setting up necessary permissions for the desktop environment or window manager and handles poweroff, reboot, suspend and hibernate via loginctl commands.

Tip: If Setup-desktop script was used to install your desktop, elogind should already be running. If unsure, verify before you proceed further.

Prerequisites

• Install and configure Polkit as it is used for authentication by elogind.

Installation

Verify if Elogind is already installed before you proceed further.

# apk add elogind # rc-update add elogind # rc-service elogind start

Configuration

Hibernation

The command to trigger hibernation is:

# loginctl hibernate

For hibernation to work, you must have a swap partition. Check

# lsblk

for a partition with the mountpoint [SWAP].

NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
nvme0n1     259:0    0 953.9G  0 disk 
├─nvme0n1p1 259:1    0   200M  0 part /boot
├─nvme0n1p2 259:2    0   100G  0 part /
├─nvme0n1p3 259:3    0   805G  0 part /home
└─nvme0n1p4 259:4    0  48.7G  0 part [SWAP]

Remember also to add a kernel parameter to resume, ie in /etc/default/grub :

Contents of /etc/default/grub

... GRUB_CMDLINE_LINUX_DEFAULT="modules=sd-mod,usb-storage,ext4,nvme quiet rootfstype=ext4 resume=/dev/nvme0n1p4"

Note the "resume=" flag with the same partition that was marked as [SWAP].

The resume process can be speed up reducing the size of the hibernation images. See the documentation for image_size in the kernel docs for the details, but writing 0 to /sys/power/image_size should make the images as small as possible.

Power management

Edit the systemwide config file /etc/elogind/logind.conf to configure handling of power events, such as suspending the computer when power button is pressed:

Contents of /etc/elogind/logind.conf

... [Login] HandlePowerKey=suspend ...

Since loginctl requires privilege escalation, allow either the user to be part of wheel group or configure doas to allow running it as an unprivileged user.

Option1:

# optionally, allow $USER root access with password
adduser $USER wheel

Option2:

Doas is used to grant permissions for suspend-to-RAM. In the doas config file /etc/doas.conf, set

permit nopass $USER as root cmd /bin/loginctl

After setting the above, suspend-to-RAM can be triggered by running

$ /bin/loginctl suspend

Troubleshooting

Verify working of elogind

When correctly configured, the loginctl command should not output No session available message.

When using a Desktop Environment or a Window Manager like Sway with SDDM, if the elogind login session is correctly configured, the following will appear:

~$ loginctl SESSION UID USER SEAT TTY c1 105 sddm seat0 c2 1000 User seat0 tty8 2 sessions listed.

No session available

If the output is No session available, such as in the case of launching Sway from tty, suspend and many other functionality will not work. The user then must configure a display manager.

It may also be necessary to install util-linux-login to enable the use of the elogind PAM module.

See also

• elogind - Gentoo Wiki
• polkit - Gentoo Wiki
• polkit - ArchWiki