`fs-ext2.so`

Linux Ext2 filesystem

Syntax:

driver ... ext2 ext2_options ... &

Options:

Where driver is one of the devb-* drivers.

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

Description:

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:

file fragments (sub-block allocation)
large files (> 2 GB)
filetype extension
compression
b-tree directories

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 NT^a	`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 Plus^a	`fs-mac.so`	N/A	N/A
177, 178, or 179	Power-Safe	`fs-qnx6.so`	`mkqnx6fs`	`chkqnx6fs`^b

^a Read-only.

^b Not usually necessary.

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

Caveats:

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.