File Sharing with MS-DOS 6.22

[jaydub101]

I have VBox 6 on a Win10 Host with an MS-DOS 6.22 Guest. My set up is:
MS Network Client 3.0
NDIS driver PCNTND.DOS
Protocol is NWLink IPX
Setup Options are: Basic Redirector and Run Network Client with Pop-up
Names are: User Name is "Joe", Computer Name is "Jim" and Workgroup name is "Workgroup" (using alias's for this exercise)
Packet driver is DIS_PKNT9.DOS

I have internet connectivity, so I know my network is up and running. I'm trying to install file sharing between the guest and host. So I've created a shared folder on my Win10 host on drive f: called "boxshare" and enabled sharing for that folder. To prepare the guest, done the following
- Copied WG1049.exe and netshar.exe to c:\net and run both executables.
- set filesharing to yes in the \NET\SYSTEM.INI file.
- the host and guest both have the same workgroup name, which is "workgroup"

All of this is as laid out in the tutorial virtualbox tutorial "Sharing_files_with_DOS". However, the next instructions don't seem to work. They are:

Once your VM reboots, you can map or share drives. Assuming that the VM computer name is DOSCLNT:
C:\> net share dosc c:\
and assuming that your host computer name is WINHOST:
C:\> net use e: \winhost\c

When I enter "C:\>net share jim c:\", I get the error message "the syntax is incorrect". I'm not sure what should follow the computer name...should that be c:\ referring to the C: drive on the DOS guest, or should it be the the drive and shared folder on the host? If the former, why is my syntax wrong?

For the second command "net use", what does "e:" refer to....host or guest and in particular which drive? When I enter "net use e: \\DESKTOP-3G94433L\boxshare", I get the return message "the computer name specified in the networth path cannot be located". DESKTOP-3G94433L is my host computer name. If I use only one backslash, I get a syntax error message.

Lastly, when I run net share from c:>, I get the screen on the attached jpg. What is the proper syntax for the "Path" field?

The attachment net share screen.jpg is no longer available

[jaydub101]

So I switched protocols to Microsoft TPC/IP and get a successful ping. I edited config.sys and added the line "INSTALL=C:\DOS\SHARE.EXE.
When I go to the command line in the DOS guest and type the following:

C:\>net use F: \\myhostcomputername\boxshare

the O/S searches for about five seconds and then returns the following error:

Error 53: The computer name specified in the network path cannot be located.

On the host in windows explorer, I can see the shared folder "boxshare" at the following path: Network>myhostcomputername>boxshare.

Just can't figure out what I'm doing wrong.

[socratis]

Moving to "Other Guests" from "Windows Hosts".

I don't think that Windows 10 and DOS speak the same sharing protocols (SMB version). You'd need to enable SMB 1.0 in Win10 (search for it, in Windows Features). And then I found what seems to be a really comprehensive HowTo: Using Samba with DOS, Win3.x or OS/2.

Disclaimer: I haven't tried it myself...

[jaydub101]

Thanks Socratis. I enabled SMB 1.0 like you suggested, but DOS still can't find the server. Dissappointing. VB Community even have a tutorial on how to do file sharing, so it seems that at one time you could read/write between DOS and Windows. I wonder what's changed since then? Maybe it worked on an XP host? Or maybe its something with Win10. Perhaps going the Freedos route is the only option now.

[andyp73]

So I switched protocols to Microsoft TPC/IP and get a successful ping.

Are you pinging by IP address or computer name?

C:\>net use F: \\myhostcomputername\boxshare

What happens if you substitute the correct IP address for myhostcomputername?

It might help narrow it down as to whether it is an issue with the share or with name resolution.

-Andy.

[michaln]

Modern Windows versions (at least Win7 and up) won't by default share files with "legacy" Microsoft clients like DOS or Win9x or NT 4. That has nothing to do with virtualization, besides the fact that people are probably much more likely to run such things in a VM than on real hardware.

Microsoft has a KB article explaining the nasty details. The upshot is that with the default settings, file sharing with a DOS client will not work no matter what you do on the DOS side.

[jaydub101]

Yes, I'm beginning to see that the problem with sharing is the security apparatus baked into Win10. So, a lot of these older posts talking about file sharing aren't really valid any more. As you indicated, the security settings in Win10 would have to be modified and I have no idea how to do that or if its even advisable. Too bad. I've seen some posts on certain settings to modify, I think in Win7 hosts, but no firm info on Win10.

I did find a poor cousin of a workaround here: https://www.lazybrowndog.net/freedos/vi ... page_id=44.
It only works with VHD, not VDI, but it does work. If you install DOS as a VHD, you can mount the VHD file in Windows 10 in Computer Management and move files in and out of the DOS guest (both ways). For importation into the guest it takes about as long as it would take to create a virtual CD in Image Burn, and you have to shut down the guest. But what's nice is that you are able to export from the DOS guest to the Win10 host. Kind of cheating, but it does work.

[jaydub101]

Thinking about it more, it probably makes sense to create a second HDD in DOS to effect transfers, and then in the DOS guest move files from drive D: to drive C: so as to avoid exposing C: to the mounting process in Win10. Just a thought.

[socratis]

it probably makes sense to create a second HDD in DOS to effect transfers

Yes, it makes perfect sense if you can mount VHDs natively on your host! It's a really great idea! But I'm not sure why you need a 2nd HD in there...

BTW, please don't even think about mounting the VHD drive while the guest is running. You're running a high risk operation of completely destroying the disk. It takes a couple of seconds to shut down and restart a DOS guest, it's not worth it.

so as to avoid exposing C: to the mounting process in Win10

Why? What are you afraid that the mounting process will do?

[jaydub101]

In a prior post you chastised someone for doing that as extremely high risk. I guess you meant if the DOS guest were still running. So I thought a second HDD might alleviate that risk. I don't think you can even open it when the DOS guest is running. So you are saying its OK to do provided the guest isnt' running?

Also, I see that I left off the last numeral in the link....so here it is

https://www.lazybrowndog.net/freedos/vi ... age_id=443

[socratis]

In a prior post you chastised someone for doing that as extremely high risk. I guess you meant if the DOS guest were still running.

Exactly! Concurrent access of the same "hard disk" is not meant to happen in consumer-grade operating systems. It takes special OSes and controllers to do that. We commoners do not have access to those OSes or controllers.

So I thought a second HDD might alleviate that risk.

It wouldn't as long as the VM was running, you'd still have the same fundamental problem; two different "computers" accessing the same resource at the same time.

I don't think you can even open it when the DOS guest is running.

Not sure, haven't tried it. Neither would I ever try it, I love my data...

So you are saying its OK to do provided the guest isnt' running?

Absolutely!

Also, I see that I left off the last numeral in the link....so here it is

I'll highlight a couple of points in that tutorial, things that I've already mentioned, and I believe that the blog author should have in red, bold, underlined!

• To mount the image: Shut down the FreeDOS guest.
• ...
• If you are done, please take care to eject the image before you startup the FreeDOS guest in VirtualBox.

[jaydub101]

So one last issue. Is there a penalty, performance or otherwise, in using VHD rather than VDI?

[socratis]

It's the "Otherwise" penalty, not the performance one.

VHDs are (AFAIK) more "fragile" as a file, easier corrupted than VDIs or VMDKs. Even Microsoft has moved on from that format to the next one, VHDX. Plus there are not enough tools or shared knowledge in these forums about VHDs, compared to the VDI format.

But, you can't mount a VDI as easy in Windows as you can a VHD. The developers are working on a host native mounting tool, but for the moment it's only available for OSX hosts. I expect it to become a reality on all hosts in the near future.

There's an expert in the forums regarding virtual disks. I really hope he takes the "bait" and give you a more thorough explanation about the VHD fragility...

[pt58]

I can offer another possible solution which I find works well for sharing a folder on a Win95 VM with a Win 10 host.
Win95 is still basically DOS with a GUI on top so I'm assuming this will work with pure DOS.
I haven't got the time or energy to set about preparing a DOS VM and setting up all the networking to try it out, but as you have already gone through all that pain, this should be fairly easy to try out.

You still need to enable the SMB1.0 protocol on the Win10 host as a first step.

The trick is to set up a shared folder with full R/W access on the DOS VM and use that for transferring files between the Host and the VM. I have found that Win10 can see shared folders on the Win95 machine (and hopefully a DOS VM) but not vice versa.

You should find that you can open a file explorer on the Win10 host and type in the UNC path to the DOS VM eg. \\DOS622VM or whatever you've called the DOS VM.
The shared folder on the DOS VM should now show up and you can pull files off it onto the host or drop files from the Host into the VM.

As I say, this definitely works on a WIN95 VM, but I can't verify it on a DOS VM.
Hope this helps.

[jaydub101]

Thanks for sharing. I looked up your prior post and I see you've laid it out pretty well. Does it work for Win98 as well?