corosync-qnetd - QNet daemon
corosync-qnetd [-46dfhv] [-l listen_addr] [-p listen_port] [-s tls]
[-c client_cert_required] [-m max_clients] [-S
is a daemon running outside of the cluster with the
purpose of providing a vote to the corosync-qdevice
model net. It's
designed to support multiple clusters and be almost configuration and state
free. New clusters are handled dynamically and no configuration file exists.
It's also able to run as non-root user - which is recommended. Connection
between the corosync-qdevice
model net client can be optionally
configured with TLS client certificate checking. The communication protocol
between server and client is designed to be very simple and allow backwards
- and its counterpart -6 are used to force IPv4 or
IPv6 communication. The default is to listen on both address
- Turn on debug logging. By default the messages sent to
syslog are purely operational, this option sends additional debug
messages. For even more detail use the -d parameter twice.
- Do not daemonize, run in the foreground.
- Show short help text
- Show version and supported communication protocol
- IP address to listen on. By default the daemon listens on
all addresses (wildcard).
- TCP port to listen on. Default port is 5403.
- Determines if TLS should be used and can be one of
on/off/required (the default is on ). on means TLS is
enabled but the client is not required to start TLS, off means TLS
is completely disabled, and required means TLS is required.
on and required require the NSS database to be properly
initialized by running the corosync-qnetd-certutil command.
- can be set to on/off. This option only makes sense
if TLS is enabled. When -c is on a client is required to
send its client certificate (default).
- Maximum simultaneous clients. The default is 0 which means
- Set advanced settings described in its own section below.
This option shouldn't be generally used because most of the options are
not safe to change.
It's generally recommended to run corosync-qnetd
as a non root user. If
you get a package from a distribution its highly possible that the packager
has done all the hard work for you. If the installation is performed from
source code, a few steps have to be taken.
First it's necessary to create an unprivileged user/group. The following
commands can be used (executed as root):
# groupadd -r coroqnetd
# useradd -r -g coroqnetd -d / -s /sbin/nologin -c "User for corosync-qnetd" coroqnetd
The next step is to set the correct owner and group on /etc/corosync/qnetd and
# chown -R coroqnetd:coroqnetd /etc/corosync/qnetd /var/run/corosync-qnetd
Some systems have the /var/run directory on a tmpfs file system which gets
discarded after a reboot. The solution is to use an initscript which takes
care of the /var/run/corosync-qnetd creation and sets the correct owner and
permissions. For systems with systemd it's possible to use a tmpfile.d
configuration file (installed by default if systemd is enabled during corosync
The last step is to make sure corosync-qnetd
is really executed as an
unprivileged user. For initscript systems it's enough to set the line
COROSYNC_QNETD_RUNAS in /etc/(sysconfig|default)/corosync-qnetd file. If the
file is not already installed then use the one provided in the corosync source
code (init/corosync-qnetd.sysconfig.example). For systemd, overwrite/copy the
corosync-qnetd.service unit file and uncomment/change the "User="
For TLS to work its necessary to create the NSS database. If pcs is used then
the following steps are not needed because pcs does them automatically.
is the tool to perform required actions. Just
# corosync-qnetd-certutil -i
If TLS is not required then simply edit /etc/(sysconfig|default)/corosync-qnetd
or systemd unit file and add the parameter -s off
in the proper
Set by the -S
option. The default value is shown in parentheses.
- Parameter passed to the listen syscall on the network
- Maximum number of send buffers for one client. (32)
- Maximum size of one send buffer (message) to be sent to a
- Maximum size of the receive buffer for a client message
(maximum allowed message size received by client). (32768)
- NSS database directory. (/etc/corosync/qnetd/nssdb)
- NSS nickname of qnetd server certificate. (QNetd Cert)
- Minimum heartbeat timeout accepted by server in ms.
- Maximum heartbeat timeout accepted by server in ms.
- Dead peer detection enabled. (on)
- How often the DPD algorithm detects dead peers in ms.
- Lock file location.
- Internal IPC socket file location.
- Parameter passed to listen syscall on the local socket.
- Maximum allowed simultaneous IPC clients. (10)
- Maximum size of a message received by IPC client.
- Maximum size of a message sent to an IPC client.