--------------------- CRITICAL ERRORS START HERE ---------------------
[2011-12-01 21:00:13] Version [1.6.3.18]Could not ping NFS server for archive
---------------------- CRITICAL ERRORS END HERE ----------------------
This error means the AMETHYST server could not find the NFS server for archiving.
Please check that the configuration for NFS IP and share is correct:
AMETHYST Webadmin Home page -> Configure Archiving
If correct, then it might be a network or PC problem. Check that the PC is up and running.