According to github topic, I wrote new entry to fstab, and after creating snapshot in Timeshift, grub-btrfs reacted:
[manjaro2 ~]# systemctl status grub-btrfs
○ grub-btrfs.service - Regenerate grub-btrfs.cfg
Loaded: loaded (/usr/lib/systemd/system/grub-btrfs.service; static)
Active: inactive (dead) since Thu 2022-06-30 22:37:12 CEST; 3s ago
TriggeredBy: ● grub-btrfs.path
Process: 1701 ExecStart=bash -c if [ -s "${GRUB_BTRFS_GRUB_DIRNAME:-/boot/grub}/grub-btrfs.cfg" ]; then /etc/grub.d/41_snapshots-btrfs; else ${GRUB_BT>
Main PID: 1701 (code=exited, status=0/SUCCESS)
CPU: 252ms
cze 30 22:37:12 manjaro2 bash[1703]: Found snapshot: 2022-06-30 22:35:19 | timeshift-btrfs/snapshots/2022-06-30_22-35-19/@ | ondemand | N/A >
cze 30 22:37:12 manjaro2 bash[1703]: Found snapshot: 2022-06-30 22:31:57 | timeshift-btrfs/snapshots/2022-06-30_22-31-57/@ | ondemand | N/A >
cze 30 22:37:12 manjaro2 bash[1703]: Found snapshot: 2022-06-30 14:55:34 | timeshift-btrfs/snapshots/2022-06-30_14-55-34/@ | ondemand | {timeshift-autosna>
cze 30 22:37:12 manjaro2 bash[1703]: Found 3 snapshot(s)
cze 30 22:37:12 manjaro2 bash[1812]: submenu 'Manjaro Linux snapshots' {
cze 30 22:37:12 manjaro2 bash[1812]: configfile "${prefix}/grub-btrfs.cfg"
cze 30 22:37:12 manjaro2 bash[1812]: }
cze 30 22:37:12 manjaro2 bash[1703]: Unmount /tmp/grub-btrfs.PVJ4JAUvNb .. Success
cze 30 22:37:12 manjaro2 systemd[1]: grub-btrfs.service: Deactivated successfully.
cze 30 22:37:12 manjaro2 systemd[1]: Finished Regenerate grub-btrfs.cfg.
[manjaro2 ~]# blkid
/dev/mapper/luks-d8359d82-cc9a-41d2-aa41-b94a70877ebd: LABEL="swap" UUID="b31123bd-6ec0-4b9f-aa39-15ec9a3f2d34" TYPE="swap"
/dev/mapper/luks-e6110c0d-7a1d-46eb-b0c7-89799bb79d61: UUID="9a26de7f-84a2-4672-8be5-79e66c2cbbf3" UUID_SUB="4f1fed35-a8ba-4aad-846f-9ec87fc761d6" BLOCK_SIZE="4096" TYPE="btrfs"
/dev/sda2: UUID="d8359d82-cc9a-41d2-aa41-b94a70877ebd" TYPE="crypto_LUKS" PARTUUID="daa79fa3-02"
/dev/sda1: UUID="e6110c0d-7a1d-46eb-b0c7-89799bb79d61" TYPE="crypto_LUKS" PARTUUID="daa79fa3-01"
##UUID of LUKS partition
[manjaro2 ~]# cat /etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a device; this may
# be used with UUID= as a more robust way to name devices that works even if
# disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
/dev/mapper/luks-e6110c0d-7a1d-46eb-b0c7-89799bb79d61 / btrfs subvol=/@,defaults 0 0
/dev/mapper/luks-e6110c0d-7a1d-46eb-b0c7-89799bb79d61 /home btrfs subvol=/@home,defaults 0 0
/dev/mapper/luks-e6110c0d-7a1d-46eb-b0c7-89799bb79d61 /var/cache btrfs subvol=/@cache,defaults 0 0
/dev/mapper/luks-e6110c0d-7a1d-46eb-b0c7-89799bb79d61 /var/log btrfs subvol=/@log,defaults 0 0
/dev/mapper/luks-d8359d82-cc9a-41d2-aa41-b94a70877ebd swap swap defaults,noatime 0 0
UUID=9a26de7f-84a2-4672-8be5-79e66c2cbbf3 /run/timeshift/backup btrfs defaults,noatime 0 0
[manjaro2 ~]# systemctl -t mount
UNIT LOAD ACTIVE SUB DESCRIPTION
-.mount loaded active mounted Root Mount
dev-hugepages.mount loaded active mounted Huge Pages File System
dev-mqueue.mount loaded active mounted POSIX Message Queue File System
home.mount loaded active mounted /home
run-timeshift-1391-backup.mount loaded active mounted /run/timeshift/1391/backup
run-timeshift-backup.mount loaded active mounted /run/timeshift/backup
run-user-1000-doc.mount loaded active mounted /run/user/1000/doc
run-user-1000-gvfs.mount loaded active mounted /run/user/1000/gvfs
run-user-1000.mount loaded active mounted /run/user/1000
sys-fs-fuse-connections.mount loaded active mounted FUSE Control File System
sys-kernel-config.mount loaded active mounted Kernel Configuration File System
sys-kernel-debug.mount loaded active mounted Kernel Debug File System
sys-kernel-tracing.mount loaded active mounted Kernel Trace File System
tmp.mount loaded active mounted Temporary Directory /tmp
var-cache.mount loaded active mounted /var/cache
var-log.mount loaded active mounted /var/log
[manjaro2 ~]# ls -l /run/timeshift/backup
razem 0
drwxr-xr-x 1 root root 252 06-30 14:49 @
drwxr-xr-x 1 root root 130 06-30 14:53 @cache
drwxr-xr-x 1 root root 12 06-30 14:50 @home
drwxr-xr-x 1 root root 192 06-30 14:55 @log
drwxr-xr-x 1 root root 210 06-30 22:35 timeshift-btrfs
So is this a new way to properly configure timeshift/btrfs/grub-btrfs?