The runtime directory

@tmpfsdir@/@sysrundir@

The run-image subdirectory of the system configuration directory is copied here during init.

• service:
  This is a scan directory containing service directories corresponding to longrun services. They are usually managed by s6-rc. Service directories added to @confdir@/system/run-image/service will be copied here by init, recognized by s6-svscan and interpreted by s6-supervise independently of s6-rc. Of course, service directories can be copied or symlinked manually to this directory.
• s6-rc and s6-rc:s6-rc-init:CoHrfy:
  s6-rc:s6-rc-init:CoHrfy is a directory used by s6-rc for state tracking, s6-rc is a symlink to it.
• log:
  This directory contains logging directories from s6-log. Some loggers may need to be up before the storage device containing the system logging directory is mounted. An example is the s6-svscan-log, which captures everything that does not go to another logger. s6-svscan-log is started even before s6-rc is initialized. s6-rc usually manages mounting any storage devices. Another example are userspace device managers, the work they do is often used to mount storage devices, they thus need to be up before mounting. This makes it necessary, that their corresponding logger logs to the tmpfs.

@tmpfsdir@/@usrrundir@

Contains user owned supervision trees grouped by user. the @tmpfsdir@/@usrrundir@/@USER1@ directory is owned by @USER1@ and can be used for anyting by this user. The user-tmpfs program exists to prepare those directories easily.

The run-image subdirectory of the user configuration directory is copied to @tmpfsdir@/@usrrundir@/${USER} during user-init.

For each @USER1@, @USER2@, ... , there is an arbitrary amount of @USERTREE@, @USERTREE@, ... subdirectories. These represent the multiple user supervision trees each user may have. Each of these has the same structure and purpose as @tmpfsdir@/@sysrundir@/, but for the user supervision tree.

The @tmpfsdir@/@usrrundir@/${USER} directory is intended to be used as an properly permissioned user specific tmpfs. A secure alternative to /tmp without the sticky bit. A practical example would be creating a directory like @tmpfsdir@/@usrrundir@/${USER}/runtime as the XDG_RUNTIME_DIR and setting the environment variable XDG_RUNTIME_DIR=@rundir@/user/${USER}/runtime.

Populating runtime directories

runtime directories are automatically populated from the configuration directory as well as s6-rc-init (see prepare-svscan).