Mounting multiple partitions to one directory

[paulbiz]

Hi,

I'm an ex- OS/2 user, been using Gentoo for about a year and a half now. One of the things I miss from OS/2 is the tvfs "Toronto Virtual File System". It basically let you create volumes (drive letters) and map different drives, files, directories into it, along with the ability to map two things to the same spot and have it automatically do load balancing by writing the next file to the mapped disk with the most free space. It was a nice easy way to combine multiple drives without needing to RAID them or to physically span the parition across multiple disks. Conflicts were not really dealt with, I think it just gave you the first matching file from the mount order, which could lead to some interesting scenarios.

Is it possible to do this in Linux? For example, let's say I have two drives mounted:

/mnt/disk1
/mnt/disk2

On disk 1, I have a "downloads" directory, say /mnt/disk1/files/downloads

On disk 2, I have a "downloads" directory, say /mnt/disk2/downloads

If I wanted to make /home/user/downloads link to those two directories, showing the contents from both as if they were one, and writing new files to either of them (the one with the most free space), automagically creating directories on the other when it gets to be it's turn (eventually they even out, and every other file is written to each drive). Is that possible using symlinks, or the mount program or something?

thanks
paul

[paulbiz]

To answer my own question... unionfs
but I'm not sure if it can do the load-balancing part...