The intent of the troubleshooting section is to introduce solutions to a number of common issues encountered by users and the tools that are available to aid in developing States and Salt code.
If your Salt master is having issues such as minions not returning data, slow execution times, or a variety of other issues, the following links contain details on troubleshooting the most common issues encountered:
In the event that your Salt minion is having issues, a variety of solutions and suggestions are available. Please refer to the following links for more information:
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 and/or master in the foreground:
salt-master -l debug salt-minion -l debug
No ports need to be opened up on each minion. For the master, TCP ports 4505 and 4506 need to be open. 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.
You can check port connectivity from the minion with the nc command:
nc -v -z salt.master.ip 4505 nc -v -z salt.master.ip 4506
There is also a firewall configuration document that might help as well.
If you've enabled the right TCP ports on your operating system or Linux distribution's firewall and still aren't seeing connections, check that no additional access control system such as SELinux or AppArmor is blocking Salt.
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
state.apply directly 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
The salt-master needs at least 2 sockets per host that connects to it, one for the Publisher and one for response port. Thus, large installations may, upon scaling up the number of minions accessing a given master, encounter:
12:45:29,289 [salt.master ][INFO ] Starting Salt worker process 38 Too many open files sock != -1 (tcp_listener.cpp:335)
The solution to this would be to check the number of files allowed to be opened by the user running salt-master (root by default):
[root@salt-master ~]# ulimit -n 1024
And modify that value to be at least equal to the number of minions x 2. This setting can be changed in limits.conf as the nofile value(s), and activated upon new a login of the specified user.
So, an environment with 1800 minions, would need 1800 x 2 = 3600 as a minimum.
There are known bugs with ZeroMQ versions less than 2.1.11 which can cause the
Salt master to not respond properly. If you're running a ZeroMQ version greater
than or equal to 2.1.9, you can work around the bug by setting the sysctls
net.core.wmem_max to 16777216. Next, set the third
net.ipv4.tcp_wmem to at least 16777216.
You can do it manually with something like:
# echo 16777216 > /proc/sys/net/core/rmem_max # echo 16777216 > /proc/sys/net/core/wmem_max # echo "4096 87380 16777216" > /proc/sys/net/ipv4/tcp_rmem # echo "4096 87380 16777216" > /proc/sys/net/ipv4/tcp_wmem
Or with the following Salt state:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
net.core.rmem_max: sysctl: - present - value: 16777216 net.core.wmem_max: sysctl: - present - value: 16777216 net.ipv4.tcp_rmem: sysctl: - present - value: 4096 87380 16777216 net.ipv4.tcp_wmem: sysctl: - present - value: 4096 87380 16777216
Currently there are no SELinux policies for Salt. For the most part Salt runs
without issue when SELinux is running in Enforcing mode. This is because when
the minion executes as a daemon the type context is changed to
The problem with SELinux arises when using salt-call or running the minion in
the foreground, since the type context stays
This problem is generally manifest in the rpm install scripts when using the
pkg module. Until a full SELinux Policy is available for Salt the solution
to this issue is to set the execution context of
salt-minion to rpm_exec_t:
# CentOS 5 and RHEL 5: chcon -t system_u:system_r:rpm_exec_t:s0 /usr/bin/salt-minion chcon -t system_u:system_r:rpm_exec_t:s0 /usr/bin/salt-call # CentOS 6 and RHEL 6: chcon system_u:object_r:rpm_exec_t:s0 /usr/bin/salt-minion chcon system_u:object_r:rpm_exec_t:s0 /usr/bin/salt-call
This works well, because the
rpm_exec_t context has very broad control over
Salt requires Python 2.6 or 2.7. Red Hat Enterprise Linux 5 and its variants
come with Python 2.4 installed by default. When installing on RHEL 5 from the
EPEL repository this is handled for you. But, if you run Salt from git, be
advised that its dependencies need to be installed from EPEL and that Salt
needs to be run with the
An extensive list of YAML idiosyncrasies has been compiled:
If the minion or master seems to be unresponsive, a SIGUSR1 can be passed to the processes to display where in the code they are running. If encountering a situation like this, this debug information can be invaluable. First make sure the master of minion are running in the foreground:
salt-master -l debug salt-minion -l debug
Then pass the signal to the master or minion when it seems to be unresponsive:
killall -SIGUSR1 salt-master killall -SIGUSR1 salt-minion
Also under BSD and macOS in addition to SIGUSR1 signal, debug subroutine set up for SIGINFO which has an advantage of being sent by Ctrl+T shortcut.
When filing an issue or sending questions to the mailing list for a problem with an unresponsive daemon this information can be invaluable.
As of release 0.17.1 you can no longer run different versions of Salt on your Master and Minion servers. This is due to a protocol change for security purposes. The Salt team will continue to attempt to ensure versions are as backwards compatible as possible.