[Discuss] nfs in virtual machines

[me at mattgillen.net (Matthew Gillen)]

All this talk of virtual machines reminded me that there might be some 
experts out there that could help with a problem that's been with me for 
a while.

I have a server that is on all the time and serves NFS.  I have a linux 
VM that runs on windows host (virtualbox), and the linux guest mounts 
the home directory from the server (to be clear, the NFS server is not 
the same box as the VM host).

The guest VM is set up for NAT.

The problem is that every 5 or 10 minutes, the machine is just not 
responsive.  'ls' on the home directory will just hang for like a 
minute.  Terminal windows are fine and can execute commands until you 
run a command that does anything with the NFS mount.  Also can't launch 
new terminals at that point because it wants to read your ~/.bashrc

Eventually it will come back and is zippy.

I'm pulling my hair out trying to figure out how to debug this.  It 
feels like a pure NFS problem; the VM host has plenty of memory and 
isn't pausing the VM; the UI in the guest is generally responsive except 
for the windows that are blocked waiting to read/write something from ~

Nothing really useful is in the syslog or journalctl.

Any ideas on where to look or things to try?

Thanks
Matt