[Unionfs] how to install unionfs?

[Erez Zadok]

In message <661811e70707162359w53daca50vade7595ea95a96bd at mail.gmail.com>, "=?BIG5?B?qkxD?=" writes:

> sir,
>        i want install unionfs in ubuntu (kernel version=2.6.20-15),so may i
> to use the latest diff ,but i don't
> know how to use the diff?can you help me ?Thank you!

It requires some experience in patching and building kernels.

This assumes that your kernel doesn't already have any unionfs patches
applied to it.

You'll need to get the matching kernel sources for your kernel first.
Presumably you can get them from ubuntu directly, because like most other
linux vendors, they probably made all kinds of modifications to their
kernel.  I assume you've unpacked your kernel sources in /usr/src/linux, in
that case, you can do something like this:

# cd /usr/src/linux
# wget http://download.filesystems.org/unionfs/unionfs-2.x/linux-2.6.20.14-u4.diff.gz
(if there's a newer 2.6.20 patch, use that instead)
# gunzip linux-2.6.20.14-u4.diff.gz
# patch -p1 < linux-2.6.20.14-u4.diff

Next, you'll need to reconfigure your kernel to turn on unionfs support.
You can use "make menuconfig" or any other kernel configuration method/tool.
Go to the Filesystems section, "Layered Filesystems" subsection, and then
enable Unionfs.

Finally, build and install your kernel, reboot, and once you're back in load
the unionfs module.  Then you can mount it.

# make
# make modules_install install
# reboot
(after reboot)
# modprobe unionfs

Well, anyway, this is a start.  if you've not patched a kernel before, it'd
probably take some trying to build up that experience.  You might have to
read up on man pages such as patch(1) and diff(1), as well as linux
kernel-build documentation.

Good luck.

Erez.