Check an entire Power-Safe filesystem for consistency (QNX Neutrino)

Note: You must be logged in as root to run this utility.


chkqnx6fs [-sv] host

Runs on:



Display header information from the superblock. The number of -v options controls which fields chkqnx6fs displays.

Note: If you specify -s, chkqnx6fs locates and verifies the active superblock, but doesn't check the filesystem itself.

Increase output verbosity. You can specify multiple -v options.
The host of the filesystem. You can specify this as a block-special device or partition (e.g. /dev/hd0t76), as a regular file, or as the root directory of a mounted fs-qnx6 filesystem (which will be resolved to the real host device).


The chkqnx6fs performs a consistency check on a Power-Safe (fs-qnx6) filesystem. The check is conducted in these passes:

  1. Locate and verify superblocks and select the newest stable one.
  2. Traverse the system inodes and bitmap files.
  3. Recursively walk the directory hierarchy from the root.

Only a stable filesystem can be checked (i.e. one that isn't going to change or be updated during the scan). A stable filesystem is one of the following:

Note: You shouldn't actually need to use chkqnx6fs in a production system (e.g. in a boot script). The design of the fs-qnx6 filesystem should (in the absence of software bugs, physical bad blocks, or malicious data modification on the raw device) make any such check unnecessary.

Summary of filesystem commands

The following table shows the shared objects and related commands for the filesystems:

Partition type Filesystem Shared object Initialize with: Check with:
1, 4, or 6 DOS mkdosfs chkdosfs
7 Windows NTa N/A N/A
11, 12, or 14 FAT32 mkdosfs chkdosfs
77, 78, or 79 QNX 4 dinit chkfsys
131 Linux (Ext2) N/A N/A
175 Apple Macintosh HFS or HFS Plusa N/A N/A
177, 178, or 179 Power-Safe mkqnx6fs chkqnx6fsb

a Read-only.

b Not usually necessary.

For more information, see the Filesystems chapter of the System Architecture guide.


# chkqnx6fs -v /dev/hd0t76
** Prelude: read and verify superblocks **
** Pass 1 : verify bitmap and inodes **
** Pass 2 : verify directory hierarchy **
** Summary: 20216/8040524 blocks, 142/62816 inodes **

Exit status:

The filesystem is consistent/stable.
An error occurred checking the filesystem (descriptive messages are written to stderr).

See also:

chkdosfs, chkfsys,, mkqnx6fs

Backing Up and Recovering Data in the Neutrino User's Guide

Power-Safe filesystem in the Filesystems chapter of the System Architecture guide

Power-Safe filesystem in the Filesystems chapter of the Neutrino User's Guide