vfs_preopen — Hide read latencies for applications reading numbered files
vfs objects = preopen
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.
This module is stackable.
preopen:names specifies the file name pattern which should
trigger the preopen helpers to do their work. We assume that
the files are numbered incrementally. So if your file names
are numbered FRAME00000.frm FRAME00001.frm and so on you would
list them as preopen:names=/FRAME*.frm/
Specifies the number of bytes the helpers should speculatively read, defaults to 1.
Number of forked helper processes, defaults to 1.
Number of files that should be speculatively opened. Defaults to the 10 subsequent 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.