Sporadic errors 290 and 291 after moving to Hyper-V VM

Sporadic errors 290 and 291 after moving to Hyper-V VM.

Sporadic errors 290 and 291 occur in the applications after moving the server to a Hyper-V virtual machine.

Problem did not occur before moving to a virtualized environment (the only change).

Clients terminate when either error occurs (as the result of a STOP condition rather than a crash).

Problems affect individual users when it occurs; it is not experienced by groups of users simultaneously.

User sessions terminate with error 290.

Batch sessions terminate with error 291.

Disabling the local backup system has no effect.

Adding the -pls startup parameter (PROLIB Swap) has no effect.

Specifying a large -mmax value has no effect.

Process Monitor reports a NETWORK ERROR on the .PL file when error 290 is reported:

 

Error 290 always references an application-related procedure library (.pl).

Procedure libraries are located on the local system but are accessed via mapped drives, where the drive mappings point to local folders.

Using standard procedure libraries (not memory mapped).



Error 291 relates to a process that writes to files on a mapped drive for a protracted period of time (a stream is opened and the file is written to over the course of the job; the stream is only closed upon completion).

The system has sufficient disk space available.
 

The problem is being caused by the virtual machine queue (VMQ) which is impacting network connectivity and/or performance.

Disable the Virtual Machine Queue in the vApp's Network Adapter > Hardware Acceleration settings:

References to other documentation:

Progress article(s):
 What does the error "Insufficient disk space or Write access denied" really mean ?
 Error 291 during the execution of the client application
 Clients running on a VMWARE environment disconnect with error 290
 Remote clients occasionally fail with error 290 when opening pl files
 prowin32 runtime error due to intermittent loss of connection to Windows mapped drives.