From Newsgroup: comp.misc

One big issue with the BSD variants is that their filesystems are not
even compatible.

Linux has a “ufs” filesystem driver which tries to be compatible with
many of them (and even with proprietary Unixes like SunOS, HP/UX and
NextStep). I tried using it on a FreeBSD volume yesterday, and got
these lines in my dmesg:

[Fri Jun 5 13:54:57 2026] ufs: You didn't specify the type of your ufs filesystem

mount -t ufs -o ufstype=sun|sunx86|44bsd|ufs2|5xbsd|old|hp|nextstep|nextstep-cd|openstep ...

>>>WARNING<<< Wrong ufstype may corrupt your filesystem, default is ufstype=old
[Fri Jun 5 13:54:57 2026] ufs: ufs_fill_super(): bad magic number

So the “5xbsd” option seemed to work, but I only needed to mount it read-only anyway, I wasn’t going to risk actually writing to it ...
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From Newsgroup: comp.misc

Lawrence =?iso-8859-13?q?D=FFOliveiro?= <[email protected]d> wrote:

One big issue with the BSD variants is that their filesystems are not
even compatible.

Not sure what you mean. The FFS has evolved over the years but most of
the BSD variants today use the same type.

Remember ext started out as a proprietary thing, and it's not completely
like normal Unix filesystems.

And yes, Linux can deal with that using the 5xbsd driver under FUSE which
is slow as hell but serviceable.

If you prefer, and many do, you can use xfs.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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From Newsgroup: comp.misc

Lawrence D?Oliveiro <[email protected]d> wrote:

One big issue with the BSD variants is that their filesystems are not
even compatible.

They are separate Operating Systems, unlike Linux distros
which all use the same kernel. So as years went on, some
divergences happened.

Linux has a ?ufs? filesystem driver which tries to be compatible with
many of them (and even with proprietary Unixes like SunOS, HP/UX and NextStep). I tried using it on a FreeBSD volume yesterday, and got
these lines in my dmesg:

<snip>

WARNING<<< Wrong ufstype may corrupt your filesystem,

default is ufstype=old

So the ?5xbsd? option seemed to work, but I only needed to mount it
read-only anyway, I wasn?t going to risk actually writing to it ...

I no longer have a FreeBSD system, but IIRC Linux never supported
write on ufs, also I think FreeBSD moved on to ufs2. Maybe that
is causing you the issues.
--
[t]csh(1) - "An elegant shell, for a more... civilized age."
- Paraphrasing Star Wars
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From Newsgroup: comp.misc

John McCue <[email protected]d> wrote:

Lawrence D?Oliveiro <[email protected]d> wrote:

One big issue with the BSD variants is that their filesystems are not
even compatible.

They are separate Operating Systems, unlike Linux distros
which all use the same kernel. So as years went on, some
divergences happened.

AIUI the idea of taking a disc from one system to another was a foreign
concept at the time these FSes were developed. Discs being large heavy
things you kept in your rack with their own controllers, why would you try
to attach one to a different kind of system? That meant things like
structures and endianness were just whatever the host system happened to be
- there wasn't the idea of serialising to an on-disc format, you just dumped out your structs to disc and read them back next time you booted.

I no longer have a FreeBSD system, but IIRC Linux never supported
write on ufs, also I think FreeBSD moved on to ufs2. Maybe that
is causing you the issues.

That's my understanding too - I always used the ufs2 target to mount on
Linux. Seems that 5xbsd is a synonym for ufs2, being the FS in FreeBSD 5.x

https://docs.kernel.org/admin-guide/ufs.html
implies it's supported read-write.

Theo
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From Newsgroup: comp.misc

On Sat, 6 Jun 2026 09:46:17 -0400 (EDT), Scott Dorsey wrote:

On Sat, 6 Jun 2026 05:53:26 -0000 (UTC), Lawrence D’Oliveiro wrote:

One big issue with the BSD variants is that their filesystems are
not even compatible.

Not sure what you mean. The FFS has evolved over the years but most
of the BSD variants today use the same type.

If the Linux driver warns against corruption if choosing the wrong
variant, then presumably the same thing can happen among the BSDs
themselves: if one BSD variant tries to write to a filesystem created
by a different variant, then exactly the same sort of corruption can
occur.

Remember ext started out as a proprietary thing, and it's not
completely like normal Unix filesystems.

I don’t know what you mean by “proprietary”, since the exts were
always open-source. They have always supported full POSIX semantics.
There has never been any subtle format variation among different Linux
distros that could lead to corruption, unlike the BSDs.

And yes, Linux can deal with that using the 5xbsd driver under FUSE
which is slow as hell but serviceable.

This is a Linux kernel module.

If you prefer, and many do, you can use xfs.

That’s how the FreeBSD system was set up, I had no choice.
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From Newsgroup: comp.misc

On 06 Jun 2026 18:28:16 +0100 (BST), Theo wrote:

John McCue <[email protected]d> wrote:

They are separate Operating Systems, unlike Linux distros which all
use the same kernel. So as years went on, some divergences
happened.

AIUI the idea of taking a disc from one system to another was a
foreign concept at the time these FSes were developed.

No, because all this divergence happened in the 1990s and onwards.

Discs being large heavy things you kept in your rack with their own controllers, why would you try to attach one to a different kind of
system?

Interesting you mention that. Proprietary platforms seemed to follow
the concept of “one size fits all” when it came to filesystem design
-- they tended not to offer a choice of filesystems. And the BSDs
followed this.

Except somehow it became “one size fits all installations of the same
BSD variant, and nothing else”.
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From Newsgroup: comp.misc

Theo <[email protected]> wrote:

John McCue <[email protected]d> wrote:

I no longer have a FreeBSD system, but IIRC Linux never supported
write on ufs, also I think FreeBSD moved on to ufs2. Maybe that
is causing you the issues.

That's my understanding too - I always used the ufs2 target to mount on Linux. Seems that 5xbsd is a synonym for ufs2, being the FS in FreeBSD 5.x

https://docs.kernel.org/admin-guide/ufs.html
implies it's supported read-write.

That implication might be misleading. The description for the
kernel config option to enable UFS contradicts it by explicitly
stating that UFS2 "is READ-ONLY supported". Although write support
for some UFS variants can be enabled with CONFIG_UFS_FS_WRITE which
is marked experimental/dangerous so Linux distros often don't
enable that even if they do build the UFS driver.

https://www.kernelconfig.io/CONFIG_UFS_FS?arch=x86&kernelversion=7.0 https://www.kernelconfig.io/CONFIG_UFS_FS_WRITE?arch=x86&kernelversion=7.0

So FreeBSD uses UFS2 while UFS(v1), used by default in other
active BSDs, has slightly better (but still weak) Linux support.
FreeBSD, NetBSD and OpenBSD all make UFS(v1) file systems which
work using the "44bsd" "ufstype" with the Linux driver.

Big deal. On the other side of the coin I once installed Linux
using Reiserfs 3 as the filesystem...

Also people who claim the BSDs have better documentation than Linux
could have a point. It doesn't take much to beat official docs that
don't agree on whether write support for a filesystem exists or
not.
--
__ __
#_ < |\| |< _#
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From Newsgroup: comp.misc

Computer Nerd Kev <[email protected]d> wrote:

Also people who claim the BSDs have better documentation than Linux
could have a point. It doesn't take much to beat official docs that
don't agree on whether write support for a filesystem exists or
not.

The man pages for BSD have examples and are mostly coherent. But also,
BSD is not subject to the high rate of random change that linux is, and consequently the documentation tends to stay correct for longer.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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From Newsgroup: comp.misc

On Sat, 6 Jun 2026 21:00:40 -0400 (EDT), Scott Dorsey wrote:

The man pages for BSD have examples and are mostly coherent. But
also, BSD is not subject to the high rate of random change that
linux is, and consequently the documentation tends to stay correct
for longer.

And yet Linux can manage more disciplined changes that don’t do random
things like break filesystem compatibility. This is why you can have
300 different Linux distros that will interoperate more freely than
half a dozen BSD variants are able to manage.
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From Newsgroup: comp.misc

Computer Nerd Kev <[email protected]d> wrote:
<snip>

So FreeBSD uses UFS2 while UFS(v1), used by default in other
active BSDs, has slightly better (but still weak) Linux support.

IIRC, NetBSD made changes to its file system in Release
10.0. So I do not know if its ffs2 is supported on Linux
either. This is what I quickly found on ffsv2.

https://wiki.netbsd.org/tutorials/acls_and_extended_attributes_on_ffs/

But, NetBSD also has zfs, though an older version. Maybe
zfs could work. But I never used ZFS on any system.


OpenBSD ffs was updated in 6.7, now it is ffs2. I do not
know if that is supported by Linux these days:

https://why-openbsd.rocks/fact/ffs2/
--
[t]csh(1) - "An elegant shell, for a more... civilized age."
- Paraphrasing Star Wars
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From Newsgroup: comp.misc

Theo wrote:

AIUI the idea of taking a disc from one system to another was a foreign concept at the time these FSes were developed. Discs being large heavy things you kept in your rack with their own controllers, why would you try
to attach one to a different kind of system?

This is a good point and it highlights something about Linux that
people miss. The ext family wasn't designed by OS developers for
their own kernel -- it was designed by people who knew the
filesystem would run on wildly different hardware under wildly
different distros. That portability constraint was there from the
start because Linux never had a "our hardware, our way" luxury.

The BSDs had the opposite problem: they could assume a coherent
stack because the project controlled the whole thing. When they
diverged, nobody planned for cross-variant portability because
why would you? You ran FreeBSD or OpenBSD, not both.

What's funny is this mirrors the Linux-vs-BSD user experience
more broadly. Linux distros fragment at the userspace level
(packaging, init, desktop) but share a kernel. BSDs share a
philosophy but fragment at the system level. Pick your
fragmentation layer.
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From Newsgroup: comp.misc

Lawrence D’Oliveiro <[email protected]d> writes:

One big issue with the BSD variants is that their filesystems are not
even compatible.

So is it Microsoft's NTFS in BSD land which is universal then?

Personally I've found NTFS the best choice between Windows, Linux,
Android phones and both Android-based and other random media players and
TVs.
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From Newsgroup: comp.misc

On Tue, 09 Jun 2026 11:25:37 +0300, Anssi Saari wrote:

Personally I've found NTFS the best choice between Windows, Linux,
Android phones and both Android-based and other random media players
and TVs.

Kind of a lowest-common-denominator, I guess. It it showing its age,
though: it has trouble dealing efficiently with lots of small files.

Remember that all those Android/Linux devices have inbuilt support for
the usual Linux filesystems. And there are probably more of them in
your house than Windows machines, nowadays.
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