Using bind-mounts instead of symlinks

[Volker Wysk]

Am Montag, den 09.03.2020, 15:41 -0400 schrieb Robert Heller:
> At Mon, 09 Mar 2020 20:04:21 +0100 "Ubuntu user technical
> support,  not for general discussions" <ubuntu-users at lists.ubuntu.com
> > wrote:
> 
> > Hi!
> > 
> > I've got a big, new SSD (1 TB) and a bigger hard disk. I want to
> > place
> > some of my data on the SSD, and some on the hard disk. 
> > 
> > This could be done with symbolic links. The home directory would
> > reside
> > on the SSD, with large parts of it being placed on the hard disk.
> > Symlinks would point from within the home directory to places on
> > the
> > HDD.
> > 
> > This has disadvantages. For one thing, you won't get a real
> > directory
> > tree under the home directory. Nautilus, for instance, won't find
> > the
> > parts on the HDD, because symbolic links aren't followed (correct
> > my
> > when I'm wrong). You can use find with the "-follow" argument,
> > however.
> 
> I can't speak about Nautilus (or any graphical file manager), since I
> don't 
> use a graphical file manager.  

It _is_ practical, sometimes. :-)

> From the shell symlinks are mostly transparent. 
> I use them all of the time and never have any issues.
> 
> > Backup becomes somewhat difficult, too. You need to backup the home
> > directory tree and the externalized parts on the HDD as well. When
> > restoring from the backup, you must be careful to specify the right
> > place of the files, which possibly aren't in the home directory
> > tree,
> > but externalised on the HDD.
> 
> You are not thinking about this properly.  You backup each file
> system 
> separately. The fact that there are symlinks on one file system (the
> SSD) 
> targeting the other (rotating rust), is not really an issue, either
> during the 
> backup or the restore.  In any case, you don't actually backup the
> home 
> directory tree, nor do you restore it either, at least not in the way
> you are 
> appearently thinking about it.  You backup the SSD and you backup the
> HDD 
> (rotating rust).  And then you may restore the SSD (which might
> include some 
> symlinks) or you restore the HDD.

I don't backup each file system separately. I backup the whole (root)
directory tree, with exclusions. The backup includes /mnt/fp, where
I've mounted my HDD. Of course the symlinks aren't followed when
backing up, that's clear. I don't think of it as an issue. 

> 
> > So I conceived the idea of using bind mounts. The parts which are
> > on
> > the HDD would be bind-mounted at places in the home directory. You
> > get
> > a clean directory tree, and everything is fine.
> > 
> > Only root can do that, but that's okay for me. What's too annoying
> > to
> > stick to this arrangement, is that for each bind-mounted directory,
> > I
> > get a hard disk icon on the desktop. 
> > 
> > I'm wondering if it is a good idea to do it with bind mounts. And
> > if
> > the icon problem can be worked around.
> 
> Using bind mounts this way is probably going to bite you sooner or
> later,
> typically.  You idea seriously abuses the point of bind mounts.

But it looks like it would work (except for that icon issue)... Is it
abuse when you use a feature according to it's specification? I'm
unsure...

Bye
Volker