How is PUPPY filesystem structured in LIVE & Frugal layouts?

[gcmartin]

Over the years, developers has introduced various ways to structure Puppy for booting. As well, over the years, meaningful documentation on the ways and means make it difficult for the new and experience members to find and correlate these structures in an easily understood instance.

This thread is a requested attempt to gather useful understanding so that users can identify the means and the layout of the PUPs they use, and what is contained in those files that users see when viewing,either, the ISO, the DVD drive if booted Live or the Frugal folder if booted frugally.

I ask community to assist with any knowledge they choose to share on this thread so that users can understand the various means of Puppy boot system layouts.

These are a few that I ask community to express their knowledge of layout (pictures sometimes help too).

I am aware of several in primary use today: The following are examples taken from Puppy ISOs:

• layouts with vmlinux, initrd, and distro's-SFS, for example:
  
• layouts with humonguous, for example:
  
• layouts with vmlinux, initrd, zdrv-SFS, and distro's-SFS, for example:
  
• there are others, for example:
  

This thread is inspired by members trying to assist on this question, here, as I can see why the OP started the thread in absence of finding a good clear explanation of the differing packaging developers would do in any PUP distro.

No matter how simplistic you offer answers, all answers can be "a useful help" to members who review this thread for better Puppy understanding. I will update this opening post from time to time as you offer any responses to help in user understanding.
For example,

• @MikeSLR provides a view of how the Puppy Linux structure processes files which end with the .sfs extension when those applications-subsystems are called upon in Puppy.
• AND, @Anikin provides both written and example visuals of Linux's filesystem where additional info is presented on the mission of the directories in Linux.

But, it has been made know via other threads, that in some PUPs, following the Linux standard is not always taken. And, it is also well-known that the filesystems in other Linux distros may, too, interpret the standard different and unique to their desire and need.

[mikeslr]

Hi gcmartin,

I realize that you only asked about Live and Frugal layouts, but thought this was as good a place as any to demonstrate what a Full install looks like. [Especially since I've had this screenshot sitting around for awhile and want to get rid of it].

The attached is a composite of two screenshots:

The top-right corner shows /, and the various folders within it, including /lib. It was superimposed on a screenshot of /lib, which shows the folders and files within that folder.

If the user is operating with a SaveFolder --rather than a SaveFile-- an examination of such SaveFolder will reveal a similar structure: folder, folders within folders, and files within a folder.

Depending on what applications the user has installed into a Frugal install using a SaveFolder, examination of / of the SaveFolder will reveal folders having some or all of the same names as those shown on the top-right corner of the screenshot; and browsing into any folder will reveal folders having some or all of the same names which would appear in a Full Install.

The same condition would be true of a SaveFile, except that you will not be able to see the contents of a SaveFile unless it is mounted or opened using a program which can edit SaveFiles.

mikesLr

[gcmartin]

The vmlinux component (kernel)
An excellent description of VMLinux is found here.
Several PUPPY Linux members have produced tools for creating the Linux kernel. Currently, the most active member is @StemSee's Kernel Builder utility found here.

The initrd component (initial ramdisk boot subsystem)

[mikeslr]

Hi All,

Hopefully gcmartin or someone who actually knows will correct any misinformation the following contains.

I'd like to be able to tell you that when you're running a Frugally Installed Pup, what you'll see in RAM (random access memory) is similar to what you see when you look at a Full install, or look into a SaveFolder. But I can't. To a large extent what you see “in RAM

[anikin]

First things first.
Before this thread goes too far, here is some *required* reading:
Filesystem Hierarchy Standard

The Filesystem Hierarchy Standard (FHS) defines the directory structure and directory contents in Unix and Unix-like operating systems.

https://en.wikipedia.org/wiki/Filesyste ... y_Standard
https://wiki.linuxfoundation.org/en/FHS
For example, what's /opt for
http://refspecs.linuxfoundation.org/FHS ... 03s13.html
or what's the purpose of /usr/bin
http://refspecs.linuxfoundation.org/FHS ... 04s04.html
If the above refs and specs sound too dull and dry for you, have a look at this lovely piece:
http://tuxradar.com/content/take-linux- ... tour/#null
and some nice visuals:
https://www.google.com/search?q=linux+f ... z3QQJc8%3D

[amigo]

Yeah, there's no way to fathom what puppy is doing without comparing it with any 'standard' distro. And really, one must understand the distro as it is installed -and understand the installer (because every installer is a mini-LiveCD.

It is, quite correctly, all done with smoke and mirrors, now known as links, union-mounts, loop devices, layers & Co. These days, distros like fedora actually use device-mapper to create COW systems which combine read-only and writable devices, file-systems, mounts, images and archives.

[mikeslr]

Thanks anikin for stepping in. I especially think your link to illustrations of the Linux File system will be helpful to newbies –both new and, like myself, perpetual-- trying to understand what's going on.

Hopefully, amigo, I made it clear that I was not trying to set out how Puppy actually works; but only how I visualize it working on those occasions when I have an interest in somehow changing an already existing Pup.

When I first started using Puppy, it was pretty much “a black box