Eric Shubert wrote:
> Joseph Sinclair wrote:
<<TRIM>>
>> Most mixed live/persistent distros use a single file loopback mounted as the overlay filesystem (via overlayfs or unionfs), including IIRC Ubuntu live/USB.  As such, the entire persistent partition is, indeed, limited to the *file* size limit of the host partition.
>> Most virtual machine systems have similar problems (which is one more reason why it's good to *not* put virtual disk files on systems using FAT or NTFS, poor windows users...).
>>
> 
> Thanks for chiming in on this, Joseph. I'm not terribly familiar with 
> unionfs/aufs, just enough to be dangerous. ;)
> 
> Can you say then, whether this single-file aspect is true for all 
> union/aufs implementations, or is it only because of the way it's used 
> by persistent distros? TIA.
> 

I've mostly seen it with loop mounted files.  I think (not sure) that UnionFS allows other filesystem combinations, but I've never seen that in practice.