A great deal of information is available via the debug logging system, if you are having issues with minions connecting or not starting run the minion in the foreground:
# salt-minion -l debug
No ports need to be opened on the minion, as it makes outbound connections to the master. If you've put both your Salt master and minion in debug mode and don't see an acknowledgment that your minion has connected, it could very well be a firewall interfering with the connection. See our firewall configuration page for help opening the firewall on various platforms.
If you have netcat installed, you can check port connectivity from the minion
$ nc -v -z salt.master.ip.addr 4505
Connection to salt.master.ip.addr 4505 port [tcp/unknown] succeeded!
$ nc -v -z salt.master.ip.addr 4506
Connection to salt.master.ip.addr 4506 port [tcp/unknown] succeeded!
The Nmap utility can also be used to check if these ports are open:
# nmap -sS -q -p 4505-4506 salt.master.ip.addr
Starting Nmap 6.40 ( http://nmap.org ) at 2013-12-29 19:44 CST
Nmap scan report for salt.master.ip.addr (10.0.0.10)
Host is up (0.0026s latency).
PORT STATE SERVICE
4505/tcp open unknown
4506/tcp open unknown
MAC Address: 00:11:22:AA:BB:CC (Intel)
Nmap done: 1 IP address (1 host up) scanned in 1.64 seconds
If you've opened the correct TCP ports and still aren't seeing connections, check that no additional access control system such as SELinux or AppArmor is blocking Salt. Tools like tcptraceroute can also be used to determine if an intermediate device or firewall is blocking the needed TCP ports.
salt-call command was originally developed for aiding in the
development of new Salt modules. Since then, many applications have been
developed for running any Salt module locally on a minion. These range from the
original intent of salt-call (development assistance), to gathering more
verbose output from calls like
When initially creating your state tree, it is generally recommended to invoke
highstates by running
from the minion with
salt-call, rather than remotely from the master. This
displays far more information about the execution than calling it remotely. For
even more verbosity, increase the loglevel using the
# salt-call -l debug state.apply
The main difference between using
salt and using
salt-call is that
salt-call is run from the minion, and it only runs the selected function on
that minion. By contrast,
salt is run from the master, and requires you to
specify the minions on which to run the command using salt's targeting
If the minion seems to be unresponsive, a SIGUSR1 can be passed to the process to display what piece of code is executing. This debug information can be invaluable in tracking down bugs.
To pass a SIGUSR1 to the minion, first make sure the minion is running in the foreground. Stop the service if it is running as a daemon, and start it in the foreground like so:
# salt-minion -l debug
Then pass the signal to the minion when it seems to be unresponsive:
# killall -SIGUSR1 salt-minion
When filing an issue or sending questions to the mailing list for a problem with an unresponsive daemon, be sure to include this information if possible.
As is outlined in github issue #6300, Salt cannot use python's multiprocessing pipes and queues from execution modules. Multiprocessing from the execution modules is perfectly viable, it is just necessary to use Salt's event system to communicate back with the process.
The reason for this difficulty is that python attempts to pickle all objects in memory when communicating, and it cannot pickle function objects. Since the Salt loader system creates and manages function objects this causes the pickle operation to fail.
When a command being run via Salt takes a very long time to return
(package installations, certain scripts, etc.) the minion may drop you back
to the shell. In most situations the job is still running but Salt has
exceeded the set timeout before returning. Querying the job queue will
provide the data of the job but is inconvenient. This can be resolved by
either manually using the
-t option to set a longer timeout when running
commands (by default it is 5 seconds) or by modifying the minion
/etc/salt/minion and setting the
timeout value to
change the default timeout for all commands, and then restarting the
Modifying the minion timeout value is not required when running commands from a Salt Master. It is only required when running commands locally on the minion.