stacd - Man Page

STorage Appliance Connector


stacd [Options...]


stacd is a system daemon that can be used to automatically connect to NVMe-oF I/O Controllers using the discovery log pages collected by stafd(8). It can also be manually configured with stacd.conf(5) to connect to I/O Controllers that otherwise cannot be found automatically.


The following options are understood:

-h,  --help

Print the help text and exit.


Print the version string and exit.

-fFILE, --conf-file=FILE

Specify a different configuration file than stacd.conf(5) (default: /etc/stas/stacd.conf).

-s,  --syslog

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


Trace ON. (default: false)


Print D-Bus IDL to FILE and exit.

Exit Status

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


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

Table 1. 

$ systemctl start stacd
Start daemon.
$ systemctl stop stacd
Stop daemon. The SIGTERM signal is used to tell the daemon to stop.
$ systemctl restart stacd
Effectively a stop + start.
$ systemctl reload stacd
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.


stacd use the GLib main loop. The GLib Python module provides several low-level building blocks that stacd 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.


stacd can automatically set up the I/O connections to discovered storage subsystems. However, stacd can also operate in a non-automatic mode based on manually entered configuration. In other words, storage subsystems can be entered in a configuration file named /etc/stas/stacd.conf. This configuration file also provides additional parameters, as log-level attributes used for debugging purposes.


The interface to stacd is D-Bus. This allows other programs, such as stacctl, to communicate with stacd. The D-Bus address is org.nvmexpress.stac.

See Also

stacd.conf(5), stacd.service(8), stacctl(1), stafd(8), org.nvmexpress.stac(5).

Referenced By

nvme-stas(7), stacctl(1), stacd.conf(5), stacd.service(8), stas-config@.service(8),, sys.conf(5).

nvme-stas 2.3.1