JFat Announce

Let me introduce a new FileSystem implementation
for our beloved JNode: JFat.

JFat, that stands for Jnode Fat, is an attempt
to implement the Microsoft FAT FileSystem following
Microsoft specifications as they are reported on
the document available at the URL:

JFat is currently an "incomplete" implementation that
only supports FAT32 and doesn't make any attempt
to support multithread: it only aims to be compatible
with Microsoft FAT, at least at the documented level,
and able to read and write FAT FileSystems that can
be shared and tested from other Operating Systems.

Without being too much technical, JFat is able to
mount a filesystem that is contained inside a 0x0b
type partition, i.e. is marked as "W95 FAT32" from
Linux fdisk, and that contains at least 65525 clusters.

To make life easy any Windows XP FileSystem larger than
few Gigabytes should be automatically mounted as a JFAT
FileSystem from jnode.

A test vmware VMDK 4Gb bootable FAT32 disk image can be download from the URL http://www.jnode.org/uploads/issues_4 as described here: http://www.jnode.org/node/843

JFat, currently, doesn't handle FAT12 (up to 4085 clusters)
or FAT16 (up to 65525 clusters) Fat filesystems: they
are mounted and handled from the FAT Jnode FileSystem.

As for any first release (and as my first attempt
to implement a complete filesystem) JFat will need
some time to be completely debugged, so, the usual
advice to be cautios on using it against "real data".

The JFat source code, around 6.000 lines of Java code
implementing the "org.jnode.fs.jfat" package, can be
found inside the "fs/src/fs/org/jnode/fs/jfat' directory
of the JNode CVS source tree.

I had a great fun implementing this code for JNode
and I hope it can be useful to the JNode community.

I have to thank (nicknames are from the JNode IRC chat)
FabienD, Hagar, peda and lsantha for their support
and the interesting chat sessions we had on the last
few months.

A special thank is for lsantha: without his patience
and support JFat haven't had any possibility to become

G. Vitillaro (aka alea on the IRC chat)

Nice work

Nice work!


JFat & Ms-Fat

I am really happy with your announcement.Am looking forward to such a great thing like this.Thanks for providing a better thing. Thanks for the developers and team.

My Personal Blog


JFat sounds like a cool tool. Getting support the the MS Windows FAT systems is great and needed. I am looking forward to start playing with the JFAT. Great work from your guys.

The secret to happiness is not in doing what one likes to do, but in liking what one has to do.

FAT has patent problem, right?

what's the influence against the PATENT of FAT M$ gotten early this year?


I think microsoft has

I think microsoft has patent on FAT but they doesn't charge using of FAT specification. For the momentn there are no real problem to implement FAT specification.

Microsoft Fat patent.

For what I read on Internet, Microsoft has been granted, in January 2006, the right on "devices" that contains Fat filesystems, like on SD cards for cameras and GPS navigators. Microsoft has the right to get money for number of devices sold up to 250.000 US$.

For what I know this do not currently apply to Fat implementations for Open Source software ... but I'm not a lawyer and not even proficient on US (or EU by the way) patent legal issues.

That is my 2 cents contribute ... let me know if someone knows technical legal issues about this topic.


You might as well ask the

You might as well ask the same question to the Linux developers.