dracut.bootup — boot ordering in the initramfs

Description

This flow chart illustrates the ordering of the services, if systemd is used in the dracut initramfs.

                                    systemd-journal.socket
                                               |
                                               v
                                    dracut-cmdline.service
                                               |
                                               v
                                    dracut-pre-udev.service
                                               |
                                               v
                                     systemd-udevd.service
                                               |
                                               v
local-fs-pre.target                dracut-pre-trigger.service
         |                                     |
         v                                     v
 (various mounts)  (various swap  systemd-udev-trigger.service
         |           devices...)               |             (various low-level   (various low-level
         |               |                     |             services: seed,       API VFS mounts:
         v               v                     v             tmpfiles, random     mqueue, configfs,
  local-fs.target   swap.target     dracut-initqueue.service    sysctl, ...)        debugfs, ...)
         |               |                     |                    |                    |
         \_______________|____________________ | ___________________|____________________/
                                              \|/
                                               v
                                        sysinit.target
                                               |
                             _________________/|\___________________
                            /                  |                    \
                            |                  |                    |
                            v                  |                    v
                        (various               |              rescue.service
                       sockets...)             |                    |
                            |                  |                    v
                            v                  |              rescue.target
                     sockets.target            |
                            |                  |
                            \_________________ |                                 emergency.service
                                              \|                                         |
                                               v                                         v
                                         basic.target                             emergency.target
                                               |
                        ______________________/|
                       /                       |
                       |                       v
                       |            dracut-pre-mount.service
                       |                       |
                       |                       v
                       |                  sysroot.mount
                       |                       |
                       |                       v
                       |             initrd-root-fs.target
           (custom initrd services)            |
                       |                       v
                       |             dracut-mount.service
                       |                       |
                       |                       v
                       |            initrd-parse-etc.service
                       |                       |
                       |                       v
                       |            (sysroot-usr.mount and
                       |             various mounts marked
                       |               with fstab option
                       |                x-initrd.mount)
                       |                       |
                       |                       v
                       |                initrd-fs.target
                       \______________________ |
                                              \|
                                               v
                                          initrd.target
                                               |
                                               v
                                    dracut-pre-pivot.service
                                               |
                                               v
                                     initrd-cleanup.service
                                          isolates to
                                    initrd-switch-root.target
                                               |
                                               v
                        ______________________/|
                       /                       |
                       |        initrd-udevadm-cleanup-db.service
                       |                       |
           (custom initrd services)            |
                       |                       |
                       \______________________ |
                                              \|
                                               v
                                   initrd-switch-root.target
                                               |
                                               v
                                   initrd-switch-root.service
                                               |
                                               v
                                          switch-root

Author

Harald Hoyer

See Also

dracut(8) bootup(7)

Referenced By

dracut-cmdline.service(8), dracut-initqueue.service(8), dracut-mount.service(8), dracut-pre-mount.service(8), dracut-pre-pivot.service(8), dracut-pre-trigger.service(8), dracut-pre-udev.service(8).

10/08/2018 dracut