how add /boot dedicated filesystem to boom

You'll need a recent version of boom (at least 1.6.0, ideally 1.6.1) and systemd (v254 or later, or v252-18 or later on RHEL9).

To create a snapshot boot entry for the system that mounts /boot and the /var LV you'd need a commands like this:

(assuming you haven't already created an OsProfile for the running system)

[root@localhost ~]# boom profile create --from-host
Created profile with os_id d5bded8:
  OS ID: "d5bded84c4f37fc29568e83ea2cb2b1dfc3d5789",
  Name: "Red Hat Enterprise Linux", Short name: "rhel",
  Version: "9.4 (Plow)", Version ID: "9.4",
  Kernel pattern: "/vmlinuz-%{version}", Initramfs pattern: "/initramfs-%{version}.img",
  Root options (LVM2): "rd.lvm.lv=%{lvm_root_lv}",
  Root options (BTRFS): "rootflags=%{btrfs_subvolume}",
  Options: "root=%{root_device} ro %{root_opts} crashkernel=1G-4G:192M,4G-64G:256M,64G-:512M resume=/dev/mapper/rhel-swap rd.lvm.lv=rhel/swap rhgb quiet",
  Title: "%{os_name} %{os_version_id} (%{version})",
  Optional keys: "grub_users grub_arg grub_class id", UTS release pattern: "el9"

Then create the boot entry using the --mount and --no-fstab options (assuming /boot is on /dev/vda1 and the /var snapshot is named rhel/var-snap):

[root@localhost ~]# boom create --title Snapshot --root-lv rhel/root-snap --no-fstab --mount /dev/vda1:/boot:xfs:defaults --mount /dev/rhel/var-snap:/var:xfs:defaults
Created entry with boot_id 4e28cfa:
  title Snapshot
  machine-id adf850dcb85441779af286c0479c528f
  version 5.14.0-427.13.1.el9_4.x86_64
  linux /vmlinuz-5.14.0-427.13.1.el9_4.x86_64
  initrd /initramfs-5.14.0-427.13.1.el9_4.x86_64.img
  options root=/dev/rhel/root-snap ro rd.lvm.lv=rhel/root-snap crashkernel=1G-4G:192M,4G-64G:256M,64G-:512M resume=/dev/mapper/rhel-swap rd.lvm.lv=rhel/swap rhgb quiet fstab=no systemd.mount-extra=/dev/vda1:/boot:xfs:defaults systemd.mount-extra=/dev/rhel/var-snap:/var:xfs:defaults
  grub_users $grub_users
  grub_arg --unrestricted
  grub_class kernel

You should then see the "Snapshot" entry in the grub menu when you reboot.

snapshotmanager / boom-boot

how add /boot dedicated filesystem to boom #38