syslogd(8) on Solnix vs Linux and the BSDs

On Solnix, syslogd is the illumos /usr/sbin/syslogd, run as the SMF service svc:/system/system-log:default. It has only six options. The important differences are the flags: -T and -t control remote logging (-T enables the UDP port), whereas -T means something else on Linux, FreeBSD, OpenBSD and NetBSD.

What Solnix runs

A default Solnix system runs the illumos syslogd at /usr/sbin/syslogd. No other variants are shipped. The service is svc:/system/system-log:default, managed with svcadm(8) and queried with svcs(1). The recommended way to allow or disallow remote logging is the SMF property svc:/system/system-log/config/log_from_remote, not the command-line flags.

Differences

Compared withTopicWhat differs
all four-T meaningSolnix -T enables the UDP port so remote messages are logged (the default). Linux -T sets local time on received messages. NetBSD -T always uses local time for network messages. FreeBSD -T is in the synopsis; its text is trimmed in the bundle. OpenBSD -T creates a TCP listen socket.
Source: Solnix syslogd(8) -T; Linux syslogd(8) -T, --local-time; NetBSD syslogd(8) -T; OpenBSD syslogd(8) -T listen_address; FreeBSD syslogd(8) SYNOPSIS
all four-t meaningSolnix -t disables the UDP port and so turns off logging of remote messages. NetBSD -t does chroot(2) to chroot_dir. Linux, FreeBSD and OpenBSD have no -t in their documented options.
Source: Solnix syslogd(8) -t; NetBSD syslogd(8) -t chroot_dir; Linux/FreeBSD/OpenBSD syslogd(8) SYNOPSIS
all fourremote logging default and controlOn Solnix, SMF property log_from_remote controls remote logging. It is false on installation, and -t/-T are equivalent to true/false settings of it (-T = true, -t = false). Without either property or LOG_FROM_REMOTE set, remote messages are logged. OpenBSD and NetBSD default to not reading the UDP socket (OpenBSD needs -u, NetBSD -s makes it secure).
Source: Solnix syslogd(8) DESCRIPTION and NOTES (log_from_remote); OpenBSD syslogd(8) -u; NetBSD syslogd(8) -s
all fourservice modelSolnix runs syslogd under SMF as svc:/system/system-log:default; use svcadm to enable, disable or restart it and svcs to query it. The Linux, FreeBSD, OpenBSD and NetBSD pages in the bundle describe no service manager integration.
Source: Solnix syslogd(8) NOTES; Linux/FreeBSD/OpenBSD/NetBSD syslogd(8) DESCRIPTION
FreeBSD, NetBSDlog socket defaultSolnix reads the STREAMS log driver /dev/log by default (-p changes it). FreeBSD defaults to /var/run/log and NetBSD to /var/run/log. OpenBSD and Linux default to the /dev/log socket.
Source: Solnix syslogd(8) -p, DESCRIPTION; FreeBSD syslogd(8) -p; NetBSD syslogd(8) -p; OpenBSD syslogd(8) -p; Linux syslogd(8) -p
all fourforeground modeSolnix has no foreground flag. -d turns on debugging and must not be used in start-up scripts or the system hangs at that point. Linux uses -n, FreeBSD and OpenBSD use -F, and NetBSD -d does not detach but is for debugging.
Source: Solnix syslogd(8) -d; Linux syslogd(8) -n; FreeBSD syslogd(8) -F; OpenBSD syslogd(8) -F, -d; NetBSD syslogd(8) -d
FreeBSD, OpenBSD, NetBSDpid fileSolnix writes /var/run/syslog.pid if possible and has no option to change it. FreeBSD uses the same default and -P changes it. Linux has -P with a different default. NetBSD writes /var/run/syslogd.pid.
Source: Solnix syslogd(8) DESCRIPTION; FreeBSD syslogd(8) -P; Linux syslogd(8) -P; NetBSD syslogd(8) DESCRIPTION
all fourconfig file and reloadSolnix reads /etc/syslog.conf (-f overrides) and rereads it on HUP, closing all files and reopening only those listed. Linux defaults to /usr/local/etc/syslog.conf. FreeBSD, OpenBSD and NetBSD default to /etc/syslog.conf. OpenBSD requires log files to exist already.
Source: Solnix syslogd(8) DESCRIPTION, -f; Linux syslogd(8) -f; FreeBSD syslogd(8) -f; OpenBSD syslogd(8) -f and DESCRIPTION; NetBSD syslogd(8) -f
all fourmissing optionsSolnix has no option for IPv4/IPv6 selection (-4/-6), bind address, remote peer filtering, or message repeat compression control. Linux, FreeBSD and OpenBSD document -4 and -6; the BSDs and Linux have bind or peer options.
Source: Solnix syslogd(8) SYNOPSIS; Linux syslogd(8) -4, -6, -b; FreeBSD syslogd(8) -4, -6, -a, -b; OpenBSD syslogd(8) -4, -6, -U
OpenBSDTLSOpenBSD syslogd can send and receive messages over TLS (-S, -C, -c, -k, -K, -V). The Solnix page documents no TLS or TCP support.
Source: OpenBSD syslogd(8) DESCRIPTION, -S, -T, -C; Solnix syslogd(8) OPTIONS
all fourmessage IDsSolnix can prefix each message with [ID msgid facility.priority] if message ID generation is enabled (see log(4D)); IDs are not shown on the console. The other pages do not document this.
Source: Solnix syslogd(8) DESCRIPTION; Linux/FreeBSD/OpenBSD/NetBSD syslogd(8) DESCRIPTION

Standards

  • POSIX: syslogd is not a POSIX.1-2024 utility.

Writing portable scripts

  • Do not rely on -T or -t in portable scripts: they mean different things on Solnix, Linux, OpenBSD and NetBSD. On Solnix set the SMF property log_from_remote with svccfg instead.
  • Do not assume a socket path or pid file: /dev/log, /var/run/log, /var/run/syslog.pid and /var/run/syslogd.pid all appear in the bundle.

Every difference here is taken from the manual pages linked above: Solnix's published page, Linux (man-pages and the GNU and util-linux manuals), FreeBSD, OpenBSD and NetBSD. Each row names its source. Where a manual is silent, this page is too. Compiled 2026-10-26. Found a mistake? Mail hackers@lists.solnix.io.