ztest(8) on Solnix vs Linux and the BSDs

On Solnix, ztest is the illumos ZFS user-space stress test at /usr/bin/ztest, filed in section 8. Its page matches NetBSD's closely. The Linux and FreeBSD pages describe a newer OpenZFS ztest with long options, a 64M default vdev size and extra RAID options. Solnix's page documents a 256M default.

What Solnix runs

A default Solnix system runs the illumos ztest at /usr/bin/ztest. No other variants are shipped. The package is pkgs.solnix.illumos-world-man.

Differences

Compared withTopicWhat differs
Linux, FreeBSDdefault vdev sizeThe Solnix page gives a default vdev size of 256M for -s. The Linux and FreeBSD pages give 64M. The same command line builds larger backing files on Solnix, which matters if /tmp is small.
Source: Solnix ztest(8) -s; Linux ztest(1) -s, --vdev-size; FreeBSD ztest(1) -s, --vdev-size
Linux, FreeBSD-f meaning in synopsisThe Solnix page documents -f path as the directory for vdev files (default /tmp). The Linux and FreeBSD synopses do not list -f, though their OPTIONS list -f, --vdev-file-directory with the same default.
Source: Solnix ztest(8) SYNOPSIS, -f; Linux ztest(1) SYNOPSIS, -f; FreeBSD ztest(1) SYNOPSIS, -f
Linux, FreeBSDlong optionsThe Linux and FreeBSD pages document GNU-style long options such as --vdevs, --run-time and --pool-name. The Solnix page documents only single-letter options.
Source: Linux ztest(1) OPTIONS; FreeBSD ztest(1) OPTIONS; Solnix ztest(8) OPTIONS
Linux, FreeBSDflags missing on SolnixThe Solnix page has no -K, -D, -S, -C, -o, -G, -M, -X or -z. Those control RAID kind, dRAID layout, vdev class state, tunables, debug dump, multi-host simulation, raidz expansion and ZIL failure rate in the Linux and FreeBSD pages.
Source: Solnix ztest(8) SYNOPSIS and OPTIONS; Linux ztest(1) SYNOPSIS and OPTIONS; FreeBSD ztest(1) SYNOPSIS and OPTIONS
Linux, FreeBSDRAID configurationSolnix -r sets raidz disks (default 4) and -R sets raidz parity (default 1). On Linux and FreeBSD, -r covers raidz or dRAID disks (4 for raidz, 16 for draid), and -K picks the kind, random by default. dRAID and expandable raidz can be chosen there.
Source: Solnix ztest(8) -r, -R; Linux ztest(1) -r, -R, -K; FreeBSD ztest(1) -r, -R, -K
Linux, FreeBSDrun time wordingThe Linux and FreeBSD DESCRIPTION says ztest runs for ten minutes by default, then says it runs for 5 minutes. Their -T default is 300s. The Solnix page gives -T default as 300 sec and does not state a ten-minute figure.
Source: Linux ztest(1) DESCRIPTION, -T; FreeBSD ztest(1) DESCRIPTION, -T; Solnix ztest(8) -T
Linux, FreeBSDenvironment variablesThe Linux and FreeBSD pages document ZFS_HOSTID and ZFS_STACK_SIZE. The Solnix page documents no environment variables.
Source: Linux ztest(1) ENVIRONMENT VARIABLES; FreeBSD ztest(1) ENVIRONMENT VARIABLES; Solnix ztest(8)
Linux, FreeBSD-B alternate ztestThe Linux and FreeBSD pages say the alternate ztest initializes the pool and runs the tests half the time, and that its lib directory is prepended to LD_LIBRARY_PATH. The Solnix page only says -B names an alternate ztest invoked after a SIGKILL.
Source: Linux ztest(1) -B; FreeBSD ztest(1) -B; Solnix ztest(8) DESCRIPTION, -B
NetBSDsame program as NetBSDThe Solnix and NetBSD pages have the same synopsis, options and defaults, including -s 256M. The text differs only in the exec reference: exec(2) on Solnix, exec(3) on NetBSD.
Source: Solnix ztest(8) SYNOPSIS, OPTIONS; NetBSD ztest(1) SYNOPSIS, OPTIONS
all fourmanual sectionSolnix files ztest in section 8. The Linux, FreeBSD and NetBSD counterparts are section 1. OpenBSD has no counterpart in the bundle.
Source: Solnix ztest(8); Linux ztest(1); FreeBSD ztest(1); NetBSD ztest(1)

Standards

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

Writing portable scripts

  • Pass only single-letter options common to all pages (-V, -E, -v, -a, -m, -r, -R, -d, -t, -g, -i, -k, -p, -T, -s). Use explicit -s because the default vdev size differs between systems.
  • Set -f explicitly to a directory with enough space, since vdev files default to /tmp on every system that documents it.

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.