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  3. nvme-stas
  4. stafd(8)

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STAFD(8) STAFD(8)

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).







  

    
    nvme-stas 2.2.1