How to create file links on a vfat filesystem of a mounted disk under Linux

filesystemshard linksymlinkvfat

I have an external drive containing different pieces of music. The drive is a vfat formatted drive to be able to work with arbitrary devices.

On the device I have music stored from different artists sorted according to their name. However, I would like to sort the single music pieces into other folders as well, without duplicating them. So, for example, the title 'Addicted to you' should be accessible from within a folder 'Avicii' but also from a different folder named e.g. 'dance'.

Is there a way I can create some kind of link on the disk? I have tried to do this with ln but got an error:

ln: failed to create symbolic link
ln: failed to create hard link

Is there another way to link those files? And to make sure it works with EVERY USB hardware (radio, TV, media set, car radio, …)?

Best Answer

You can certainly create a directory of links to your music in the structure you've described, if it's anything but a FAT filesystem, but FAT doesn't support links, so you'd have to create Windows LNK files (aka shortcuts).

NOTE: Incidentally you may be able to create LNK files using either of these tools. These tools are described as: allowing you to create Windows Shortcut files (extension .LNK) without needing a Windows OS.

But often it's better to create play list files and leave the music in some standardized structure or as a single sub-directory with other sub-directories within it.

To organize the MP3 headers you can use MusicBrainz's tool Picard to make sure the ID3 tags are all up to date on your collection.

There are many tools such as Clementine for constructing playlists. It's discussed here in this AU Q&A titled: Need a playlist creator for linux that will do relative paths.

Related Solutions

How to Create Symbolic Links with Wildcards in Linux

You might want to do that:

for dir in dir1 dir2
do
  [[ ! -d /somedir/$dir ]] && mkdir /somedir/$dir    
  find /media/sd*/$dir -type f -exec bash -c \
    '[[ ! -f /somedir/'$dir'/$(basename $1) ]] && ln -s $1 /somedir/'$dir'/' foo {} \;
done

This create symbolic links in /somedir/dir1/ (resp. dir2) pointing to all files present under /media/sd*/dir1 (resp. dir2). This script doesn't preserve hierarchy that might be present under the source directories.

Edit: Should you want all the links to be placed in a single directory, here is a slightly modified version:

[[ ! -d /somedir/data ]] && mkdir /somedir/data    
find /media/sd*/dir[12] -type f -exec bash -c \
    '[[ ! -f /somedir/data/$(basename $1) ]] && ln -s $1 /somedir/data/' foo {} \;
done

Am I hammering the SSD by keeping a symlink on it

It's fine, for many reasons.

First, the concern with flash drives is the number of writes, not the number of reads.

Second, this concern applies to older or cheaper drives with poor firmware or poor drivers, but not to modern drives on modern operating systems. Modern SSD have good enough wear leveling and modern OSes have drivers that distinguish overwrite from erase (TRIM) so it takes a very long time before the number of writes starts to become a concern. At this age, magnetic drives are often dead from mechanical-related reasons such as humidity or dust in the wrong place or mechanical damage.

Reading through a symbolic link may update its access time depending on the system configuration. Linux defaults to updating a file's access time only once a day. So even if there was a concern over the number of writes to the drive, one write would be one day, not one access through the symbolic link.

The kernel keeps information about the symbolic link in its disk cache like any other information it reads from the disk. It doesn't keep a cache that says “/var/Nextcloud_Data/filename redirects to /mnt/HDDfs/Nextcloud_Data/filename”, but it maintains a cache that says “/var/Nextcloud_Data is a symbolic link whose target is /mnt/HDDfs/Nextcloud_Data”. This means that as long as the cache entry is still present, it won't read from the drive. This has no bearing on how often the access time is updated: that's a function of when the file is accessed, not of when the information about the file is transferred from the drive.

Best Answer

Related Solutions

How to Create Symbolic Links with Wildcards in Linux

Am I hammering the SSD by keeping a symlink on it

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