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diff --git a/difference_between_mnt_and_media.html b/difference_between_mnt_and_media.html new file mode 100644 index 0000000..f9ffb01 --- /dev/null +++ b/difference_between_mnt_and_media.html @@ -0,0 +1,77 @@ +<!doctype html> +<html lang="en"> +<meta charset="utf-8"> +<meta name="viewport" content="width=device-width, initial-scale=1"> +<meta name="author" content="aki"> +<meta name="tags" content="linux, unix, file, filesystem, hierarchy, standard, media, mnt, mount"> +<link rel="icon" type="image/png" href="cylo.png"> +<link rel="stylesheet" type="text/css" href="style.css"> + +<title>Difference Between /mnt and /media</title> + +<nav><p><a href="https://ignore.pl">ignore.pl</a></p></nav> + +<article> +<h1>Difference Between /mnt and /media</h1> +<p class="subtitle">Published on 2020-06-12 19:00:00+02:00 +<p>In this article I will try to answer questions like: <i>What is the difference between /mnt and /media in FHS and +*nixes?</i>, <i>Why was /media added to FHS?</i>, and perhaps <i>What is the purpose of /mnt, and what is it for +/media?</i> +<p>To be fair, I'm somehow conflicted now. For some people the answer is so simple that they don't bother to write it +down. I'm serious. It's not like I've ever been optimistic about stackoverflow or other subsites of stackexchange, but +that one answer really gave me a good chuckle. I won't link it, because it almost feels like name shaming, but hell as +long as it's there, you'll figure out your way, won't you? +<p>Now, now. One could use no brain at all, and say that the descriptions in the standard are different, therefore they +are different. Completely discarding things like intentions, history, purposes or use cases. They are different, because +they are different. That is in fact true. It's hard to deny something that is clearly visible. Let's take a look at +them:</p> +<blockquote cite="https://refspecs.linuxfoundation.org/FHS_3.0/fhs-3.0.pdf"> +<b>3.11. /media : Mount point for removable media</b><br> +This directory contains subdirectories which are used as mount points for removable media such as floppy disks, cdroms +and zip disks. +</blockquote> +<blockquote cite="https://refspecs.linuxfoundation.org/FHS_3.0/fhs-3.0.pdf"> +<b>3.12. /mnt : Mount point for a temporarily mounted filesystem</b><br> +This directory is provided so that the system administrator may temporarily mount a filesystem as needed. The content of +this directory is a local issue and should not affect the manner in which any program is run. +</blockquote> +<p>Based on those, the usual answer is: /mnt is for system administrator and /media is for the system itself. In other +words: /mnt is for you and /media is not. This answer is quite satisfying, unless you actually read it. The 3.11 does +not say a word about who mounts stuff in /media. Even the rationale section doesn't. However, it does mention the reason +why /media was added: to stop adding mount points to root (e.g. /cdrom, /floppy). +<p>It also mentions that e.g. /mnt/cdrom and derivatives have been used as temporary mount points for removable media. +The only reason why the /media was added is because of, and I quote, tradition of using /mnt directly as a mount point. +<p>This means, that the standard partially acknowledges that /mnt and /media are interchangeable and actually can be +equivalent in how they are used. The wordings of both sections are different. That's undeniable. On the other hand, the +meaning is left to be discussed. Or is it? +<p>Originally, there have been voices that said something among the lines of: "Ay folks, ain't those the same?" Even in +<a href="https://bugs.linuxfoundation.org/show_bug.cgi?id=27">the bug report from 2003</a> that introduced this change +to FHS in 2.3 version. They all have been ignored. Year later, +<a href="https://bugs.linuxfoundation.org/show_bug.cgi?id=49">the question was asked again</a>, and the answer was what +we know now: /mnt is for temporary mount points which may not be media. +<p>What is not media? Where to draw a certain line between mounted zip file and a floppy disk? How long does a gate +needs to be to be considered a tunnel? What is the difference between "removable" and "temporary" in this particular +case? Is this really the moment we get into discussion of semantics and of what is "medium"? I feel like I already did +this pun on this blog. +<p>If I want to write a script that automatically and temporarily mounts a filesystem of one of my microcomputers +whenever they are available in the local network. Should that go to /media or /mnt? Is the sshfs a medium or not? +I mean, it's between my filesystem and the actual mounted things in the microcomputer filesystem, but is it really? +Are media limited to physical things like cd, floppy or usb drives? +<p>The difference is so ambiguous and unspecified, that it just feels completely surreal to me. Moreover, this slight +changes to understanding of what "removable media" is, and what it perhaps could become, and what people will mount in +future, was also originally pointed out. It feels like a good time to revisit those points.</p> +<img src="difference_between_mnt_and_media-1.png" alt="tunnel is a gate, but longer"> +<p>One more question remains. Is this separation needed in any sense? I think not. In my home system I swiftly use more +than one automatic manager for mounting various things: from USB drives to whole external devices with their own +operating system. I use the very same directory to manually manage temporary devices. I am yet to run into a +significant issue with this approach. +<p>To summarize, there is no particular difference between /media and /mnt in FHS. If anything /media has a defined +structure of subdirectories user can expect to find in it, and /mnt doesn't. In various implementations of FHS there +might be some conventions and traditions added on top of that like: /media is for stuff that is mounted automatically +by the system, and /mnt is for user or sysadmin to use. Overall, the use cases overlap, and it was known from the very +beginning, but it was ignored due to reasons. +<p>Originally, /media was added in FHS 2.3 as a part that was not included in 2.2 from 2.2-beta release. The goal was +to limit creation of temporary mount points in the /. Did it work out? I think not, considering that it could easily be +substituted by /mnt or vice versa. +</article> +<script src="https://stats.ignore.pl/track.js"></script> |