I shall correct the apparent omissions in some of the points;
First and foremost, underlying any and all previous and present points is the following, undeniable fact: One SHOULD NOT run ANY journaling file system on a non-block device backed loop, under Linux, due to the current implementation of the main-line loop driver!!!
[Ask Linus or anyone else in the know, for that matter. - @fanthom - One of those things you can not just script your way out of!] There is no exception to this rule unless the loop driver itself is physically altered or replaced, including the accompaning util-linux, mount etc. (Which is what most have been doing since the beginning of time for that precise reason.)
The reason I proposed the perceived importance of the Default File System choice is two fold;
1) Porteus likely ending up in a frugal install on (removable) USB drives, due to its intended use/nature, the correct file system choice will have a much bigger performance impact than a regular, full installation on traditional (legacy) hardware.
1a) While differences of major file systems are usually dependent on their use the one
thing that became apparent - and well documented out there - that EXT4 is
undeniably "The" worst choice of all available FS when running on flash media. (Just
how "bad" that can be debated but that it is the worst is hardly questionable.)
2) There is wide and long-standing evidence that there are two main factors which turn off new users from a any distribution (or anything else, for matter);
A) An ugly, cumbersome, unintuitive user interface;
B) A file system corruption and consequent data loss.
Now, if Porteus is used solely as intended, as a live system, essentially reliant on its read-only modules then the only obvious choice (under Linux) is ext2 by its very nature.
In our experience (with Slax) however, we found that unless the read-only, modular nature (as intended) can be easily and reliably maintained (WORKING modules created, downloaded, etc.), a great majority of new(er) users will simply continue to install (e.g. "dump") EVERYTHING into the persistence portions of their installations where the choice and the implementation of the default file system will make or brake a distro!!
In short, how Porteus is intended to be used and how it most likely will end up being used is two wildly different things!! -Unless, of course, the modules and their management is absolutely perfect, including function and reliability, requiring minimal user interaction.
As long as this later holds true - e.g. "perfect" in the true Biblical sense - then ext2 it is, as there is no other, intelligent choice. Said "perfection", however, is yet to be observed "in the wild"!
Just as importantly, where is the "average user" going to keep his mp3 library and baby/cat photos?? -Will there be a read-only module for those, too?
were you using XFS as the native filesystem on your block devices, running it as the default filesystem inside the initrd and /dev/root (i.e., changing the default initrd/linuxrc, which I believe are set to create virtual ext2 systems for both Slax and porteus v1.0),
The XFS case is ONLY (naturally) applicable to "Persistence".
Ext2 remains for everything read-only. (Why in hell would anyone change that, to etx4 no less???)
your first post in this thread included your mkfs and mount options for the Corsair Voyager drive, as follows:...
... I have tried to recreate this on my end, but have repeatedly failed to establish a loop device as the external log device
Let me corrected some obvious omissions - see: the first and most essential point - where all the mount (and other) options, as illustrated for XFS, ONLY hold with a block device (partition, etc.) backed loop - as is always the case!
All that said let me throw out a few sentences, just in lead-words, trying to give some context to what otherwise may seem like a purely academic exercise;
- Currently only data-centers and workstation use ext 4 and not very often;
- USB is the obvious future choice because A) nobody wants to be wired; B) existing infrastructure; C) power requirements - versus SCSI; D) cloud computing; E) upcoming performance.
- Who is the "average user" and what does he want from a Distro? Experts will - continue to - "roll their own" (modules) and beginners jump ship the moment they loose grandma's pictures. Who is Porteus for? Why will it make top 10 on Distro Watch? (If that's a metric?)
(There is no such thing as "the average user" in OSS because those are called "windows users" and between them and Apple they constitute 97.2% of the "average" eyeballs.)
- Why/How did Mint come from obscurity and shot to the top in record time. What did they do? (and it wasn't much radical innovation.)
- Why was Slax so successful, then suddenly stopped and there is still no Slax 7.0, yet? (and No, its not because Thomas is still hanging dry-walls.) Did the "average user" download it a few million times? (No!) Who and why did?