systemd is a system and service manager, replacement for SysVinit and Upstart. After a six months shift, during which it has been more granularly tested, Fedora 15 brings in, by default, a new system daemon whose code is designed from scratch, with the objective to take the maximum advantage offered by modern Linux kernel.
With systemd, Fedora 15 boots-up faster, particularly on SSD; native systemd service configuration files (or units) are much easier to understand and configure compared to sysvinit scripts, as systemd uses
.service files instead of bash script; all daemons are sorted into their own Linux cgroups, which you may explore beneath
/cgroup/systemd in the file system hierarchy; administrative features of the init system are considerably extended.
Refer to https://fedoraproject.org/wiki/Systemd for more complete information on systemd in Fedora.
Lennart Poettering (lpoetter AT redhat.com)
4kB Sector disk boot support
Booting 4kB sector disks in UEFI environments is now supported.
/var/run and /var/lock
/var/run and /var/lock are now mounted from tmpfs, and hence emptied on reboot. Applications must ensure to recreate their own files/dirs on startup, and cannot rely that doing this at package installation will suffice. It is possible to use systemd's tmpfiles.d/ mechanism to recreate directories and files beneath /var/run and /var/lock on boot, if necessary. See tmpfiles.d(5) for details (http://0pointer.de/public/systemd-man/tmpfiles.d.html).