This VFS module is part of the samba(7) suite.
This module assists applications that want to read numbered files in sequence with very strict latency requirements. One area where this happens in video streaming applications that want to read one file per frame.
When you use this module, a number of helper processes is started that speculatively open files and read a number of bytes to prime the file system cache, so that later on when the real application's request comes along, no disk access is necessary.
preopen:names = /pattern/
preopen:num_bytes = BYTES
preopen:helpers = NUM-PROCS
preopen:queuelen = NUM-FILES
The original Samba software and related utilities were created by Andrew Tridgell. Samba is now developed by the Samba Team as an Open Source project similar to the way the Linux kernel is developed.
The PREOPEN VFS module was created with contributions from Volker Lendecke and the developers at IBM.