NAME

       stafd - STorage Appliance Finder

SYNOPSIS

       stafd [OPTIONS...]

DESCRIPTION

       stafd is a system daemon that can be used to automatically locate and connect to NVMe-oF Discovery
       Controllers using mDNS service discovery. It can also be manually configured with stafd.conf(5) to
       connect to Discovery Controllers that cannot be located using mDNS.

OPTIONS

       The following options are understood:

       -h, --help
           Print the help text and exit.

       --version
           Print the version string and exit.

       -fFILE, --conf-file=FILE
           Specify a different configuration file than stafd.conf(5) (default: /etc/stas/stafd.conf).

       -s, --syslog
           Send messages to syslog instead of stdout. Use this when running stafd as a daemon. (default: false).

       --tron
           Trace ON. (default: false)

       --idl=FILE
           Print D-Bus IDL to FILE and exit.

EXIT STATUS

       On success, 0 is returned, a non-zero failure code otherwise.

DAEMONIZATION

       stafd is managed by systemd. The following operations are supported:

       Table 1.
       ┌─────────────────────────────────────┬───────────────────────────────────────┐
       │Command                              │ Description                           │
       ├─────────────────────────────────────┼───────────────────────────────────────┤
       │           $ systemctl start stafd   │ Start daemon.                         │
       ├─────────────────────────────────────┼───────────────────────────────────────┤
       │           $ systemctl stop stafd    │ Stop daemon. The SIGTERM signal is    │
       │                                     │ used to tell the daemon to stop.      │
       ├─────────────────────────────────────┼───────────────────────────────────────┤
       │           $ systemctl restart stafd │ Effectively a stop + start.           │
       ├─────────────────────────────────────┼───────────────────────────────────────┤
       │           $ systemctl reload stafd  │ Reload configuration. This is done in │
       │                                     │ real time without restarting the      │
       │                                     │ daemon. The SIGHUP signal is used to  │
       │                                     │ tell the daemon to reload its         │
       │                                     │ configuration file. Note that         │
       │                                     │ configuration parameters that affect  │
       │                                     │ connections (e.g. kato), will not     │
       │                                     │ apply to existing connections. Only   │
       │                                     │ connections established after the     │
       │                                     │ configuration was changed will        │
       │                                     │ utilize the new configuration         │
       │                                     │ parameters.                           │
       └─────────────────────────────────────┴───────────────────────────────────────┘

DESIGN

       stafd use the GLib main loop. The GLib Python module provides several low-level building blocks that
       stafd requires. In addition, many Python modules "play nice" with GLib such as dasbus (D-Bus package) and
       pyudev (UDev package).  GLib also provides additional components such as timers, signal handlers, and
       much more.

       stafd connects to the avahi-daemon using D-Bus. The avahi-daemon, or simply Avahi, is an mDNS discovery
       service used for zero-configuration networking (zeroconf).  stafd registers with Avahi to automatically
       locate Central Discovery Controllers (CDC) and Direct Discovery Controllers (DDC). When Avahi finds
       Discovery Controllers (DC), it notifies stafd which connects to the DC with the help of the libnvme
       library. Once a connection to a DC is established, stafd can retrieve the discovery log pages from that
       DC and cache them in memory.

CONFIGURATION

       stafd can automatically locate discovery controllers (DC) with the help of Avahi and connect to them.
       However, stafd can also operate in a non-automatic mode based on manually entered configuration. In other
       words, DCs can be entered in a configuration named /etc/stas/stafd.conf. This configuration file also
       provides additional parameters, such as log-level attributes used for debugging purposes.

D-BUS API

       The interface to stafd is D-Bus. This allows other programs, such as stafctl, to communicate with stafd.
       The D-Bus address is org.nvmexpress.staf.

SEE ALSO

       stafd.conf(5), stafd.service(8), stafctl(1), org.nvmexpress.staf(5).