Linux Ext2 filesystem


driver ... ext2 ext2_options ... &

Runs on:



Where driver is one of the devb-* drivers.

Turns off work-arounds for corrupt volumes created by the buggy 1.19 version of mke2fs.


The Ext2 filesystem (fs-ext2.so) provides transparent access to Linux disk partitions. This implementation supports the standard set of features found in Ext2 versions 0 and 1.

Sparse file support is included in order to be compatible with existing Linux partitions. Other filesystems can only be "stacked" read-only on top of sparse files. There are no such restrictions on normal files.

If an Ext2 filesystem isn't unmounted properly, a filesystem checker is usually responsible for cleaning up the next time the filesystem is mounted. Although the fs-ext2.so module is equipped to perform a quick test, it automatically mounts the filesystem as read-only if it detects any significant problems (which should be fixed using a filesystem checker).

The following features are not currently supported:

Note: This filesystem uses UTF-8 encoding for presentation of its filenames; attempts to specify a filename not using UTF-8 encoding will fail (with an error of EILSEQ).

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 fs-dos.so mkdosfs chkdosfs
7 Windows NTa fs-nt.so N/A N/A
11, 12, or 14 FAT32 fs-dos.so mkdosfs chkdosfs
77, 78, or 79 QNX 4 fs-qnx4.so dinit chkfsys
131 Linux (Ext2) fs-ext2.so N/A N/A
175 Apple Macintosh HFS or HFS Plusa fs-mac.so N/A N/A
177, 178, or 179 Power-Safe fs-qnx6.so mkqnx6fs chkqnx6fsb

a Read-only.

b Not usually necessary.

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


Although Ext2 is the main filesystem for Linux systems, we don't recommend using fs-ext2.so as a replacement for the QNX 4 filesystem (fs-qnx4.so). Currently, we don't support booting from Ext2 partitions. Also, the Ext2 filesystem relies heavily on its filesystem checker to maintain integrity; this and other support utilities (e.g. mke2fs) are not currently available for QNX Neutrino.