Randomly cannot write to network devices

[James Moe]

opensuse 42.1 linux 4.1.12-1-default x86_64 host: linux guest: os/2 VB: 5.0.10; bridged network

The guest mounts several remote volumes and a few printers using PEER (SMB, NetBIOS) services. Sometime in the last several months the guest has had times when it cannot write to the remote devices. The transfer times out, whether for file output or printing.

There is nothing obvious that indicates when this might occur; one moment it writes, the next moment it does not. It appears completely random. The issue does not occur on Mac OS/X.

I have attached two PCAPs that detail both a successful and failed transaction.

[James Moe]

Failed transaction

[James Moe]

Successful transaction

[michaln]

Obvious question: Does the same problem happen with the default PCnet emulation and the driver that comes with OS/2?

Does "the issue does not occur on Mac OS/X" mean that identical VM connecting to the same server does not have the problem when running on a different host?

[James Moe]

Does the same problem happen with the default PCnet emulation and the driver that comes with OS/2?

Yes. That was one of the first things I tried when troubleshooting this problem. The network interface was the default of PCNet, as are the other VMs currently. I changed one instance to Intel to see if it made any difference; it did not.

Does "the issue does not occur on Mac OS/X" mean that identical VM connecting to the same server does not have the problem when running on a different host?

Yes.

At least so far. By that I mean that the issue did not arise in all of the guests simultaneously; it was more of a slow infestation of sorts across the linux-hosted VMs. Eventually all linux-hosted instances of os/2 exhibited the problem.

This is what is particularly mysterious about the issue: Initially no problem, worked great. Then some VMs showed no difficulty while others randomly refused to write. I even swapped VMs between two computers; the problem followed the instance which seems to imply a VBox issue.

A final test: I reverted one installation of VirtualBox to v4.2.36. It made no difference. (Hmm. I did not change the Additions drivers; do they affect the network connection? I shall try that.)