sync(8) on Solnix vs Linux and the BSDs
On Solnix, sync is the illumos sync, a no-argument command that runs the sync(2) primitive to flush all unwritten system buffers to disk. Unlike Linux sync, it takes no file operands or options. The BSD pages describe the same plain no-argument command.
The manual pages
What Solnix runs
A default Solnix system runs the illumos sync, found at /usr/bin/sync, /usr/sbin/sync and /sbin/sync. No other variants are shipped. The Solnix page is in section 8; the Linux page is in section 1.
Differences
| Compared with | Topic | What differs |
|---|---|---|
| Linux | file operands | Linux sync accepts FILE operands and syncs only those files or their containing file systems. The Solnix synopsis is just 'sync', with no operands, and the page describes only a flush of all buffers. Source: Solnix sync(8) SYNOPSIS, DESCRIPTION; Linux sync(1) SYNOPSIS, DESCRIPTION |
| Linux | -d and -f options | Linux sync has -d (--data: file data only, no unneeded metadata) and -f (--file-system: sync the file systems containing the files). The Solnix page documents no options, so a script using them cannot be assumed to work on Solnix.Source: Linux sync(1) -d, --data, -f, --file-system; Solnix sync(8) SYNOPSIS |
| Linux | --help and --version | Linux sync documents --help and --version. The Solnix page documents no options at all.Source: Linux sync(1) --help, --version; Solnix sync(8) SYNOPSIS |
| Linux | underlying calls | The Linux page points to fdatasync(2), fsync(2), sync(2) and syncfs(2) for its persistence guarantees. The Solnix page says only that sync runs the sync system primitive, and refers to sync(2). Source: Linux sync(1) BUGS, SEE ALSO; Solnix sync(8) DESCRIPTION, SEE ALSO |
| Linux | persistence guarantee wording | The Linux page warns that persistence guarantees vary per system. The Solnix page says sync flushes all previously unwritten system buffers to disk, so that all file modifications up to that point are saved. The manual does not say more than that. Source: Linux sync(1) BUGS; Solnix sync(8) DESCRIPTION |
| FreeBSD, OpenBSD, NetBSD | shutdown advice | The FreeBSD, OpenBSD and NetBSD pages say that reboot(8) or halt(8) are generally preferable to sync for shutting down. The Solnix page says only that sync must be called to ensure file system integrity if the system is to be stopped, and does not mention reboot or halt. Source: FreeBSD/OpenBSD/NetBSD sync(8) DESCRIPTION; Solnix sync(8) DESCRIPTION |
| FreeBSD, OpenBSD, NetBSD | same interface | Solnix and all three BSDs document a bare 'sync' with no options or operands, which calls sync(2). For a plain 'sync' invocation there is no documented difference in arguments. Source: SYNOPSIS of Solnix, FreeBSD, OpenBSD and NetBSD sync(8) |
| FreeBSD | syncer reference | The FreeBSD page also refers to syncer(4). The Solnix page has no such reference. Source: FreeBSD sync(8) SEE ALSO; Solnix sync(8) SEE ALSO |
Standards
- POSIX: sync is not a POSIX.1-2024 utility.
- Solnix: The Solnix page's SEE ALSO lists sync(2) and attributes(7); its text in the bundle states no interface stability level.
Writing portable scripts
- Call plain 'sync' with no options or operands in portable scripts.
-d,-fand file arguments are documented only for Linux. - Do not rely on sync alone to shut down a system. The BSD pages recommend reboot(8) or halt(8) for that.
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.