FUSE

This page describes how to setup FUSE (filesystem in userspace) inside a container.

FUSE is a filesystem in which data and metadata are provided by an ordinary userspace process. The filesystem can be accessed normally through the kernel interface.

Preparations

To use FUSE you need the following:

1. OpenVZ kernel version 028test005 or higher
2. Fuse lib
3. Any FUSE-based filesystem

In the examples below sshfs is used.

Setup

Kernel

• Download appropriate kernel from openvz.org or compile kernel with CONFIG_FUSE_FS option set
• Debian/Ubuntu: You can alternatively add the line fuse into /etc/modules, and apply immediately with the command:

  modprobe --first-time fuse

Userspace

You have to fuse libraries and some fuse filesystem modules (here we use sshfs as an example).

The best way to have it installed is to use the packages from your distro vendor. An alternative is compiling the stuff from source.

Gentoo

# emerge sys-fs/sshfs-fuse

Fedora

# yum install fuse-sshfs

Debian/Ubuntu

Debian 5.0 (lenny)

FUSE cannot be installed due to udev/hotplug dependency (explained in bug report 503953)

Ubuntu, Debian 6.0 (squeeze), Debian 4.0 (etch) and older

# apt-get install sshfs

(Debian 4.0 note: see Installing udev in VE based on Debian-4.0)

Compiling from source

If there are no packages provided for you distribution, you have to compile from source.

First, compile libfuse in a container without kernel module

# vzctl enter 100
# tar xzf fuse-2.6.0.tar.gz
# cd fuse-2.6.0
# ./configure --disable-kernel-module
...
# make
...
# make install

Note: Sometimes libfuse.so.X is unseen by your programs. Usually this file is installed in /usr/local/lib directory so don't forget to add this directory into your /etc/ld.so.conf and then run ldconfig.

Next, download and compile filesystem.

# vzctl enter 100
# tar xzf sshfs-fuse-1.7.tar.gz
# cd sshfs-fuse-1.7
# ./configure
...
# make
...
# make install

Container tuning

You need to make a character device named /dev/fuse and grant your container permissions to it

# vzctl set 100 --devices c:10:229:rw --save
...
# vzctl exec 100 mknod /dev/fuse c 10 229
...

Or more simply:

# vzctl set 103 --devnodes fuse:rw --save
...

Note that restart (or moving to root container device cgroup before mounting) might be required.

Mounting filesystem

After this you may try to mount FUSE in a container.

# vzctl enter 100
# sshfs root@foo.org:/root /mnt/foo.org.root

Unmounting filesystem

In case of sshfs after umounting an appropriate daemon must be killed. This may be done by the following command:

# fusermount -u mountpoint

Using fusectl filesystem

Fusectl is a helper filesystem for FUSE. You may mount it in a container as well.

# vzctl enter 100
# mount -t fusectl none /fuse_ctl

External links

• FUSE site