NAME

       mhddfs - The driver combines a several mount points into the single one.

SYNOPSIS

        mhddfs /dir1,/dir2[,/path/to/dir3] /path/to/mount [-o options]
        mhddfs /dir1 dir2,dir3 /mount/point [-o options]
        ...
        fusermount -u /path/to/mount

   fstab record example:
       mhddfs#/path/to/dir1,/path/to/dir2 /mnt/point fuse defaults 0 0

       mhddfs#/dir1,/dir2,/dir3 /mnt fuse logfile=/var/log/mhddfs.log 0 0

OPTIONS

       with an -o option1,option2...  you can specify some additional options:

   logfile=/path/to/file.log
       specify a file that will contain debug information.

   loglevel=x
       0 - debug messages

       1 - info messages

       2 - standard (default) messages

   mlimit=size[m|k|g]
       a  free  space size threshold If a drive has the free space less than the threshold specifed then another
       drive will be choosen while creating a new file.  If all  the  drives  have  free  space  less  than  the
       threshold specified then a drive containing most free space will be choosen.

       Default value is 4G, minimum value is 100M.

       This option accepts suffixes:
              [mM] - megabytes

              [gG] - gigabytes

              [kK] - kilobytes

       For an information about the additional options see output of:
              mhddfs -h

DESCRIPTION

       The  file  system allows to unite a several mount points (or directories) to the single one. So a one big
       filesystem is simulated and this makes it possible to combine a  several  hard  drives  or  network  file
       systems.  This system is like unionfs but it can choose a drive with the most of free space, and move the
       data between drives transparently for the applications.

       While writing files they are written to a 1st hdd until the hdd has the free space (see  mlimit  option),
       then they are written on a 2nd hdd, then to 3rd etc.

       df will show a total statistics of all filesystems like there is a big one hdd.

       If  an  overflow arises while writing to the hdd1 then a file content already written will be transferred
       to a hdd containing enough of free space for a file. The  transferring  is  processed  on-the-fly,  fully
       transparent for the application that is writing. So this behaviour simulates a big file system.

   WARNINGS
       The  filesystems  are combined must provide a possibility to get their parameters correctly (e.g. size of
       free space). Otherwise the writing failure can occur (but  data  consistency  will  be  ok  anyway).  For
       example it is a bad idea to combine a several sshfs systems together.

       Please read FUSE documentation for a further conception.

COPYRIGHT

       Distributed under GPLv3

       Copyright (C) 2008 Dmitry E. Oboukhov <dimka@avanto.org>

                                                  February 2008                                        mhddfs(1)