Lennart Poettering opublikował na swoim blogu porównanie systemd z SysVinit i Upstart. Jest to liczący sobie około 18 miesięcy projekt, a jego celem ma być stworzenie nowego daemona init dla systemów Linux, który zunifikuje cały proces startu systemu. Aktualnie jest tak, iż każda dystrybucja posiada własny zestaw skryptów startowych, które były diametralnie różne pomiędzy sobą. Teraz dużą część najczęściej wykonywanych podczas startu systemu rzeczy zajmie się systemd.
W dalszym etapie startu systemu – gdy są uruchamiane usługi systemowe działają serwisy systemd, które są przenośne pomiędzy dystrybucjami. Dzięki temu programiści nie muszą pisać osobnych skryptów startowych daemona do każdej dystrybucji, a mogą za jednym razem dostarczyć go wraz z systemd.
Aktualnie dystrybucjami, które zaadoptowały nowego daemona są Fedora 15, openSUSE, Mandriva, Arch, Frugalware i Debian.
Poniższa tabela ilustruje porównanie możliwości SysVinit, Upstart oraz SystemD:
| sysvinit | Upstart | systemd | |
|---|---|---|---|
| Interfacing via D-Bus | no | yes | yes |
| Shell-free bootup | no | no | yes |
| Modular C coded early boot services included | no | no | yes |
| Read-Ahead | no | no[1] | yes |
| Socket-based Activation | no | no[2] | yes |
| Socket-based Activation: inetd compatibility | no | no[2] | yes |
| Bus-based Activation | no | no[3] | yes |
| Device-based Activation | no | no[4] | yes |
| Configuration of device dependencies with udev rules | no | no | yes |
| Path-based Activation (inotify) | no | no | yes |
| Timer-based Activation | no | no | yes |
| Mount handling | no | no[5] | yes |
| fsck handling | no | no[5] | yes |
| Quota handling | no | no | yes |
| Automount handling | no | no | yes |
| Swap handling | no | no | yes |
| Snapshotting of system state | no | no | yes |
| XDG_RUNTIME_DIR Support | no | no | yes |
| Optionally kills remaining processes of users logging out | no | no | yes |
| Linux Control Groups Integration | no | no | yes |
| Audit record generation for started services | no | no | yes |
| SELinux integration | no | no | yes |
| PAM integration | no | no | yes |
| Encrypted hard disk handling (LUKS) | no | no | yes |
| SSL Certificate/LUKS Password handling, including Plymouth, Console, wall(1), TTY and GNOME agents | no | no | yes |
| Network Loopback device handling | no | no | yes |
| binfmt_misc handling | no | no | yes |
| System-wide locale handling | no | no | yes |
| Console and keyboard setup | no | no | yes |
| Infrastructure for creating, removing, cleaning up of temporary and volatile files | no | no | yes |
| Handling for /proc/sys sysctl | no | no | yes |
| Plymouth integration | no | yes | yes |
| Save/restore random seed | no | no | yes |
| Static loading of kernel modules | no | no | yes |
| Automatic serial console handling | no | no | yes |
| Unique Machine ID handling | no | no | yes |
| Dynamic host name and machine meta data handling | no | no | yes |
| Reliable termination of services | no | no | yes |
| Early boot /dev/log logging | no | no | yes |
| Minimal kmsg-based syslog daemon for embedded use | no | no | yes |
| Respawning on service crash without losing connectivity | no | no | yes |
| Gapless service upgrades | no | no | yes |
| Graphical UI | no | no | yes |
| Built-In Profiling and Tools | no | no | yes |
| Instantiated services | no | yes | yes |
| PolicyKit integration | no | no | yes |
| Remote access/Cluster support built into client tools | no | no | yes |
| Can list all processes of a service | no | no | yes |
| Can identify service of a process | no | no | yes |
| Automatic per-service CPU cgroups to even out CPU usage between them | no | no | yes |
| Automatic per-user cgroups | no | no | yes |
| SysV compatibility | yes | yes | yes |
| SysV services controllable like native services | yes | no | yes |
| SysV-compatible /dev/initctl | yes | no | yes |
| Reexecution with full serialization of state | yes | no | yes |
| Interactive boot-up | no[6] | no[6] | yes |
| Container support (as advanced chroot() replacement) | no | no | yes |
| Dependency-based bootup | no[7] | no | yes |
| Disabling of services without editing files | yes | no | yes |
| Masking of services without editing files | no | no | yes |
| Robust system shutdown within PID 1 | no | no | yes |
| Built-in kexec support | no | no | yes |
| Dynamic service generation | no | no | yes |
| Upstream support in various other OS components | yes | no | yes |
| Service files compatible between distributions | no | no | yes |
| Signal delivery to services | no | no | yes |
| Reliable termination of user sessions before shutdown | no | no | yes |
| utmp/wtmp support | yes | yes | yes |
| Easily writable, extensible and parseable service files, suitable for manipulation with enterprise management tools | no | no | yes |
Prócz tego dostępne natywne opcje usług:
| sysvinit | Upstart | systemd | |
|---|---|---|---|
| OOM Adjustment | no | yes[1] | yes |
| Working Directory | no | yes | yes |
| Root Directory (chroot()) | no | yes | yes |
| Environment Variables | no | yes | yes |
| Environment Variables from external file | no | no | yes |
| Resource Limits | no | some[2] | yes |
| umask | no | yes | yes |
| User/Group/Supplementary Groups | no | no | yes |
| IO Scheduling Class/Priority | no | no | yes |
| CPU Scheduling Nice Value | no | yes | yes |
| CPU Scheduling Policy/Priority | no | no | yes |
| CPU Scheduling Reset on fork() control | no | no | yes |
| CPU affinity | no | no | yes |
| Timer Slack | no | no | yes |
| Capabilities Control | no | no | yes |
| Secure Bits Control | no | no | yes |
| Control Group Control | no | no | yes |
| High-level file system namespace control: making directories inacessible | no | no | yes |
| High-level file system namespace control: making directories read-only | no | no | yes |
| High-level file system namespace control: private /tmp | no | no | yes |
| High-level file system namespace control: mount inheritance | no | no | yes |
| Input on Console | yes | yes | yes |
| Output on Syslog | no | no | yes |
| Output on kmsg/dmesg | no | no | yes |
| Output on arbitrary TTY | no | no | yes |
| Kill signal control | no | no | yes |
| Conditional execution: by identified CPU virtualization/container | no | no | yes |
| Conditional execution: by file existance | no | no | yes |
| Conditional execution: by security framework | no | no | yes |
| Conditional execution: by kernel command line | no | no | yes |
