SMB/CIFS file migration engine
FME lets sysadmins migrate open files (holding rangelocks and oplocks) that are being used by client applications in a DFS namespace, from one filer to another without disruption. Hence the name virtualization. Client applications don’t know that files are being moved at the remote end. My work has been in the CIFS datapath, tracking and restoring open file metadata such as rangelocks and oplocks, and also helping migration processes track changes in a file’s data while it’s being migrated. It’d be very cool to a network filesystem developer or even a sysadmin, to see a Wireshark packet capture of the orchestrated steps.
This work was, for various reasons, done in Windows land, as a driver. Yes, I know.. ugh yuck bleh, but I got to explore a bit of Windows land :).