> From: CAREY SCHUG via talk <talk@gtalug.org>

> before going further, since my disks are empty, based upon this from the internet:
>
>   MBR is compatible with legacy and older operating systems that do
>   not support GPT. On the other hand, if you have a newer computer
>   with UEFI firmware, GPT is recommended for better compatibility
>   and support for modern features.Jul 11, 2023
>
> should i format with a GPT partition table?  IIRC every system I have
> seen (other than Sun) has had a MBR partition table.  to make sure my
> older computers can access it (hopefuly won't need to), will any
> operating system that supports 4 terabyte filesystems support GPT?

There are lots of partitioning methods.  For example *BSD.

MBR is old.  It was a simple hack based on how the IBM PC booted.  Don't
use it.  Aracana: the primary partition table is embedded in the boot
block, the first block of the disk.

Any computer that requires MBR is old and obsolete.  If you are running a
recent Linux on such old hardware, you can still use GPT: Linux will fake
up enough of an MBR that a BIOS system will be able to boot from a GPT
disk.

So: use MBR unless you have some reason not to.

> practically and realistically, I would still suggest that gparted could
> and should recognize a few of the most common file-systems, including
> microsoft and apple.

You could propose that the the gparted or libparted teams.  They might
even accept a patch to do it.

I personally would not find the idea appealing.

A better fix might be to issue a diagnostic that clearly told the user
what's up.  What it says now didn't work for you.

It's not as if gparted / libparted / fatresize is perfect.  I find this
quite inconvenient: <https://github.com/ya-mouse/fatresize/issues/25>

> ditto linux itself.

As has been explained earlier, linux can be configured to do what you
want.  You could petition your distro to do that.  Such a petition could
come in the form of a proposed patch.


> As I understand it, linux for some time has recognized GPT partition
> tables, even though it would always create MBR, so if it doesn't have to
> recognize microsoft formats, the same argument could be made that it
> should (historically have) ONLY recognized MBR partition tables.

???

Linux doesn't "always create MBR" and hasn't for at least as long as I
have cared.

> Will linux access an amiga filesystem?  Willow?  Netware?  CP/M?  I
> suspect the number of filesystems a running LINUX can actually access is
> small enough that adding code to recognize them without a partition
> table entry is reasonable.

"Linux" isn't one thing.  Minimally, it is the kernel.  Maximally it is
some or all distros.

In a random system, chances are that a recognition of a CP/M filesystem is
a false positive.  Don't do that!

Almost NO disks with systems on them are unpartitioned.  Only the odd USB
stick, flash memory card, and floppy disks (remember those?).


> Has microsoft changed?  Last I knew (thought I knew), it could not
> access or be aware of ext4 files at all unless special modifications
> were applied to it.

So?

> And "irregardless" (intentionally trying to add some levity to this) I
> would hope WE could be one (or two, or three) better then Microsoft.

It depends on what "better" is.

> In practical terms, I am not going to walk into Microcenter and buy a spinning/solid state/usb drive with an Amiga file-system on it.  A new and easy to acquire drive will contain
> --a partition table that identifies the file-systems on it)
> --an empty partition table
> --a microsoft filesystem
> --if removed from a computer sold with linux, an EXT4 or maybe one of a short list, but I suspect ONLY with a partition table.

A disk with no partition table is just odd or new.

A USB stick or SD card from a store contains stuff that you probably
should not trust.  Just wipe it.

> And once I have defined partitions, gparted and/or the linux install
> process WILL format it at least in linux and (some?) microsoft formats,
> so it DOES understand them.  I have never tried formatting a partition
> for amiga with gparted...  but if so, might that be useful for running
> an amiga emulator?

Sadly, Amiga etc. issues are not mainstream.

> Since apparently disks with one of a few microsoft filesystems are
> "common", I think it is reasonable for both Linux AND gparted to
> recognize them.

As explained, it can be configured to do so.
You have been invited to do that configuration.

> another aside, just out of curiosity: If I find a mainframe storage
> array (in a dumpster, or "fell off a truck") made from commodity disks,
> do they have one of the two partition tables, and a filesystem we might
> know about, or just some hidden binary that only the mainframe
> controller knows about?

The word "mainframe" isn't clear.

The storage arrays that get thrown out probably don't have SATA drives.

They probably have some RAID structure so no single disk has a whole
filesystem.

The filesystem might well be a Linux one since most SANs are built on
Linux.

I kind of remember IBM OS/360 disk drive formats: VTOC.  Horrible, even 50
years ago.

I certainly own disks orphaned by lack of hardware support.  ST506 anyone?

Anyway, the real problem is probably that we haven't explained how you
should think about your problem.  With the correct models in you head,
this stuff should be easier to understand.  Consider keeping notes about
your learning venture and write it up.  People who know this stuff forget
what it was like to learn it.

For example, I don't think that there is a signature that lets you
reliably recognize a CP/M filesystem (actually, the filesystem evolved).

The partition table entry for a partition specifies a partition type. 
If you don't have a partition table, there is nothing that tells the
system that type (that may or may not matter).

Summary: if you don't like something in Linux, and the maintainers (of
what?) don't seem to care, fix it yourself.  In the process, you will
probably learn why things are done the way they are.  But there is a real
chance that you can get your improvement adopted.  Try that with
Microsoft.

Example: <https://github.com/paolostivanin/OTPClient/issues/384>

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