shared folder when minix3 is the guest OS on VirtualBox

[xsli2]

Hi:

My computer is Mac, with VirtualBox installed. I have installed minix3 as guest OS. Now, I am trying to find a way that I can transfer files between the guest OS minix3 and the host OS MAC X. At the bottom of this web page:

http://wiki.minix3.org/doku.php?id=usersguide:runningonvirtualbox

mount -t vbfs -o share=NAME none /mnt

I did exactly as suggested. On the host OS, I created a folder called shared_folder. In VirtualBox, click Settings icon, etc. Then on the minix3 terminal, I typed the following command as user root:

mount -t vbfs -o share=shared_folder none /mnt

I got the error message saying "Cannot mount 'none' on mnt/. No such file or directory". I have read the man mount page and still no clue.

Thank you very much.

[David van Moolenbroek]

Hello,

On Monday, October 19, 2015 at 9:20:36 AM UTC+2, xsli2 wrote:

mount -t vbfs -o share=shared_folder none /mnt

I got the error message saying "Cannot mount 'none' on mnt/. No such file or directory".

You are using the right syntax, and MINIX3 vbfs has been in a working shape in all of recent history, so there is no obvious reason why it should fail. The one thing that concerns me is that your quoted error message does not match the output of the MINIX3 mount command in several ways. Did you really transcribe it ad verbum? In general, the "No such file or directory" error would mean that you specified a mount directory that did not exist (e.g., you do not have a /mnt directory for some reason).

Regards,
David

[xsli2]

David:

Thank you. I have two MINIX 3 installed as guest OS on VirtualBox. One is the most current one, version 3.3.0 and one is the book version 3.1.0. With your encouragement, I went back and retried.

Indeed, on version 3.3.0, the mount command worked! (I don't know why it didn't last time, maybe typo)

On version 3.1.0(the book version), the command does not work and the message is:

Usage: mount [-r] special name

            mount -s special

Thank you for your help.

[David van Moolenbroek]

Hey,

On Thursday, October 22, 2015 at 5:57:09 PM UTC+2, xsli2 wrote:

Indeed, on version 3.3.0, the mount command worked!

Great to hear!

On version 3.1.0(the book version), the command does not work [..]

That is indeed expected - vbfs was added in MINIX 3.2.1.

Regards,
David

[Heiko Eißfeldt]

Hi,

I am using Minix 3.3.0 on VirtualBox on Ubuntu 14.04 on amd64.

I observed the following error when using shared folders with the vbfs file system.
After mounting I tried to compile some C source files located under the shared folder with clang.

The clang compiler complained with:
fatal error: file 'make.c' modified since it was first processed
1 error generated.
for almost every source file.

The problem vanished when I compiled with a copy of the source tree from the native file system.

BTW: This error message vanished also under vbfs when the source file was shortened enough.
Of course then the compiler complained about the errors I had introduced by shortening, but that was expected...

So, i conclude probably there is a bug in the implementation of the vbfs file system.

To reproduce try to compile a not too short C source file from a vbfs mounted directory with clang.
My example file had a size of 53,1 kilobytes.

Regards, Heiko

[r0ller]

Hi All,

I just want to add to Heiko's observation that the same happens with vmware as well. I thought it to be a vmware issue since I found some article on some vmware site where they couldn't come up with any workaround/solution for the issue. Unfortunately, I can't recall the error message exactly but it's pretty similar to what Heiko got under VirtualBox.

Regards,

r0ller

[Antoine LECA]

On 27/10/2015 20:12, Heiko Eißfeldt wrote:
> I observed the following error when using shared folders with the vbfs file
> system.

> fatal error: file 'make.c' modified since it was first processed

Supplementary information: this diagnostic is misleading: while it used
to be triggered when the source file's st_mtime changed with respect to
the cached information (hence the text), right now it only checks
whether the *size* changes (according to the comments):

llvm/dist/clang/lib/Basic/SourceManager.cpp, line 136 ff.

//Check that the file's size is the same as in the file entry (which may
// have come from a stat cache).
if (getRawBuffer()->getBufferSize()!=(size_t)ContentsEntry->getSize()) {
if (Diag.isDiagnosticInFlight())
Diag.SetDelayedDiagnostic(diag::err_file_modified,
ContentsEntry->getName());
else
Diag.Report(Loc, diag::err_file_modified)
<< ContentsEntry->getName();

Buffer.setInt(Buffer.getInt() | InvalidFlag);
if (Invalid) *Invalid = true;
return Buffer.getPointer();
}

Also err_file_modified is a good moniker for searches through source.

My educated guess is that mtime comparisons were dropped because of too
much false negatives due to granularity problems...

Antoine

[r0ller]

Just for the record: as indicated on the minix3 github page in the issue created for this problem, compiling in a shared folder works fine when tracking current or with the dev. snapshot of 19.11.2014 which makes cross-platform development a whole lot easier:) Thanks!