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).