vfs_preopen - Hide read latencies for applications reading numbered files
vfs objects = preopen
This VFS module is part of the samba
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 = /pattern/
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:num_bytes = BYTES
Specifies the number of bytes the helpers should
speculatively read, defaults to 1.
preopen:helpers = NUM-PROCS
Number of forked helper processes, defaults to 1.
preopen:queuelen = NUM-FILES
Number of files that should be speculatively opened.
Defaults to the 10 subsequent files.
This man page is part of version 4.8.7 of the Samba suite.
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.