systemd System and Service Manager DETAILS: http://0pointer.de/blog/projects/systemd.html WEB SITE: http://www.freedesktop.org/wiki/Software/systemd GIT: git@github.com:systemd/systemd.git https://github.com/systemd/systemd.git GITWEB: https://github.com/systemd/systemd MAILING LIST: http://lists.freedesktop.org/mailman/listinfo/systemd-devel IRC: #systemd on irc.freenode.org BUG REPORTS: https://github.com/systemd/systemd/issues AUTHOR: Lennart Poettering Kay Sievers ...and many others LICENSE: LGPLv2.1+ for all code - except src/basic/MurmurHash2.c which is Public Domain - except src/basic/siphash24.c which is CC0 Public Domain - except src/journal/lookup3.c which is Public Domain - except src/udev/* which is (currently still) GPLv2, GPLv2+ REQUIREMENTS: Linux kernel >= 3.12 Linux kernel >= 4.2 for unified cgroup hierarchy support Kernel Config Options: CONFIG_DEVTMPFS CONFIG_CGROUPS (it is OK to disable all controllers) CONFIG_INOTIFY_USER CONFIG_SIGNALFD CONFIG_TIMERFD CONFIG_EPOLL CONFIG_NET CONFIG_SYSFS CONFIG_PROC_FS CONFIG_FHANDLE (libudev, mount and bind mount handling) udev will fail to work with the legacy sysfs layout: CONFIG_SYSFS_DEPRECATED=n Legacy hotplug slows down the system and confuses udev: CONFIG_UEVENT_HELPER_PATH="" Userspace firmware loading is not supported and should be disabled in the kernel: CONFIG_FW_LOADER_USER_HELPER=n Some udev rules and virtualization detection relies on it: CONFIG_DMIID Support for some SCSI devices serial number retrieval, to create additional symlinks in /dev/disk/ and /dev/tape: CONFIG_BLK_DEV_BSG Required for PrivateNetwork and PrivateDevices in service units: CONFIG_NET_NS CONFIG_DEVPTS_MULTIPLE_INSTANCES Note that systemd-localed.service and other systemd units use PrivateNetwork and PrivateDevices so this is effectively required. Optional but strongly recommended: CONFIG_IPV6 CONFIG_AUTOFS4_FS CONFIG_TMPFS_XATTR CONFIG_{TMPFS,EXT4,XFS,BTRFS_FS,...}_POSIX_ACL CONFIG_SECCOMP CONFIG_CHECKPOINT_RESTORE (for the kcmp() syscall) Required for CPUShares= in resource control unit settings CONFIG_CGROUP_SCHED CONFIG_FAIR_GROUP_SCHED Required for CPUQuota= in resource control unit settings CONFIG_CFS_BANDWIDTH For UEFI systems: CONFIG_EFIVAR_FS CONFIG_EFI_PARTITION We recommend to turn off Real-Time group scheduling in the kernel when using systemd. RT group scheduling effectively makes RT scheduling unavailable for most userspace, since it requires explicit assignment of RT budgets to each unit whose processes making use of RT. As there's no sensible way to assign these budgets automatically this cannot really be fixed, and it's best to disable group scheduling hence. CONFIG_RT_GROUP_SCHED=n Note that kernel auditing is broken when used with systemd's container code. When using systemd in conjunction with containers, please make sure to either turn off auditing at runtime using the kernel command line option "audit=0", or turn it off at kernel compile time using: CONFIG_AUDIT=n If systemd is compiled with libseccomp support on architectures which do not use socketcall() and where seccomp is supported (this effectively means x86-64 and ARM, but excludes 32-bit x86!), then nspawn will now install a work-around seccomp filter that makes containers boot even with audit being enabled. This works correctly only on kernels