flucFScheck is using FUSE to mount an existing directory in some other folder. Each access to the mounted folder will be logged in order to gather information if this access is supported by the real flucFS. Every access is then re-directed to the real directory without change.

Dependencies

Kernel module

The fuse kernel module must be loaded in order to use any fuse filesystem. This kernel module is usually installed with the linux kernel.

This can be checked with

     lsmod | grep fuse

To load it, just run

     modprobe fuse

with root permissions.

In unusual circumstances, FUSE support might be built into the kernel image.

Library

flucFScheck depends on the FUSE user space library. This library and the required utilities are installed with

     yum install fuse fuse-libs
     zypper install fuse libfuse2
     apt-get install fuse
     pacman -S fuse3 fuse2

Usage

The current version of the FUSE library is 3.1.1 and uses a slightly different API than older versions (starting with 2). It is possible to have both versions of the FUSE library installed at the same time. Since some Linux distributions only provide an older version (2) two executables are shipped: flucFScheck and flucFS2check

In case only an older version is available the executable flucFScheck will NOT work. Use flucFS2check instead when executing any of the following commands.

To mount the folder /var/data on the folder /home/hugo/mydata execute this command:

     flucFScheck -l logfile /var/data /home/hugo/mydata

If this is started from within the folder /home/hugo it can be abbreviated with

     flucFScheck -l logfile /var/data mydata

If no logfile is specified, the flucFS will NOT run as daemon and the logging is done to stderr.

To unmount the filesystem execute

     fusermount -u /home/hugo/mydata

or, if it was not running as a daemon, just hit <Ctrl>-c

After it is unmounted all data was written to the logfile. The contents will help us at limes datentechnik to determine if the real flucFS will have any issues with the logged accesses.

Known issues

If a mount command fails with this message:

    fuse: failed to open /dev/fuse: Permission denied

Solution: The permissions of the device node /dev/fuse must allow read and write for any user in order to mount a FUSE filesystem by a user other than root. This can be done by executing

    chmod ugo+rw /dev/fuse

If a mount command fails with this message:

    version `FUSE_2.8' not found (required by ./flucFS2check)

the FUSE library is too old for the shipped flucFScheck.

Solution:

  1. Get a newer version of libfuse.so , at least 2.8

  2. Contact limes datentechnik to provide You with an version of flucFS2check, built for such an old library. 2.8.0 was released on August 18th 2009 (see: FUSE releases)