I’m guilty as charged with obsessive compulsion disorder when it comes to my files. Nothing more so than my music collection. I’ve spent more time sorting it through the years than I’d like to think about.

An annoying thing with this behavior is that I have to move files from time to time across physical disks and partitions. This can be quite tiresome and time consuming.

Let me present mhddfs. It’s a filesystem in userspace that allows you to mount several physical drives into one fixed mount point. Doesn’t have to be physical drives either, can be partitions or plain directories as well.

df -h /mnt/music*:

Filesystem                          Size  Used Avail Use% Mounted on
/dev/sdc1                           916G  840G   30G  97% /mnt/music
/dev/sdb1                           916G  788G   82G  91% /mnt/music2
/dev/sdd1                           1.8T  126G  1.6T   8% /mnt/music3
/mnt/music;/mnt/music2;/mnt/music3  3.6T  1.8T  1.7T  51% /mnt/music4
total                               7.2T  3.5T  3.4T  51% -

As you can see, the first three drives are mounted in /mnt/music4. Everything on sdb1, sdc1 and sdd1 can be found at that mount point. If I decide to stop using mhddfs, I can do so at any time without any form of data loss. Files are written to the disk with enough free space.

mhddfs#/mnt/music,/mnt/music2,/mnt/music3   /mnt/music4 fuse defaults,user,allow_other 0 0