Different between booting emergency and rescue

[huyvl3-fptcloud]

RH134 said: "The emergency target keeps the root file system mounted read-only, while the rescue target waits for the sysinit.target unit to complete, so that more of the system is initialized, such as the logging service or the file systems."

But I'm still not clear in distinguishing between these two types of targets, is there any more specific example to compare?

[shura]

Hi @huyvl3-fptcloud 

Please, look at dependencies of both targets. The result give you chance to compare those two targets. More importent diff really is: local-fs.target - mount of local file systems,  swap.target - swap initialization, many services under sysinit.target

No such in emergency.target, even root file system in read only mode.

Good luck

root@notebook:~# systemctl list-dependencies rescue.target
rescue.target
○ ├─rescue.service
○ ├─systemd-update-utmp-runlevel.service
● └─sysinit.target
● ├─dev-hugepages.mount
● ├─dev-mqueue.mount
● ├─dracut-shutdown.service
● ├─import-state.service
○ ├─iscsi-starter.service
● ├─kmod-static-nodes.service
○ ├─ldconfig.service
● ├─lvm2-lvmpolld.socket
● ├─lvm2-monitor.service
○ ├─multipathd.service
● ├─plymouth-read-write.service
● ├─plymouth-start.service
● ├─proc-sys-fs-binfmt_misc.automount
○ ├─selinux-autorelabel-mark.service
● ├─sys-fs-fuse-connections.mount
● ├─sys-kernel-config.mount
● ├─sys-kernel-debug.mount
● ├─sys-kernel-tracing.mount
○ ├─systemd-ask-password-console.path
● ├─systemd-binfmt.service
○ ├─systemd-boot-random-seed.service
○ ├─systemd-firstboot.service
○ ├─systemd-hwdb-update.service
○ ├─systemd-journal-catalog-update.service
● ├─systemd-journal-flush.service
● ├─systemd-journald.service
○ ├─systemd-machine-id-commit.service
● ├─systemd-modules-load.service
○ ├─systemd-pcrmachine.service
○ ├─systemd-pcrphase-sysinit.service
○ ├─systemd-pcrphase.service
● ├─systemd-random-seed.service
○ ├─systemd-repart.service
● ├─systemd-sysctl.service
○ ├─systemd-sysusers.service
● ├─systemd-tmpfiles-setup-dev-early.service
● ├─systemd-tmpfiles-setup-dev.service
● ├─systemd-tmpfiles-setup.service
● ├─systemd-udev-trigger.service
● ├─systemd-udevd.service
○ ├─systemd-update-done.service
● ├─systemd-update-utmp.service
● ├─cryptsetup.target
● ├─integritysetup.target
● ├─local-fs.target
● │ ├─-.mount
● │ ├─boot-efi.mount
○ │ ├─ostree-remount.service
● │ ├─systemd-fsck-root.service
● │ ├─systemd-remount-fs.service
● │ └─tmp.mount
● ├─swap.target
● │ └─dev-disk-by\x2duuid-c30bad8a\x2db053\x2d4bb3\x2db238\x2d2c6d5bf26b0a.sw>
● └─veritysetup.target
root@notebook:~# systemctl list-dependencies emergency.target
emergency.target
○ └─emergency.service
root@notebook:~#