Using bind-mounts instead of symlinks

[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.  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.

> 
> 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.

> 
> Regards,
> Volker
> 
> 

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