1VFS_PREOPEN(8) System Administration tools VFS_PREOPEN(8)
2
6 vfs_preopen - Hide read latencies for applications reading numbered
7 files
8
10 vfs objects = preopen
11
13 This VFS module is part of the samba(7) suite.
14 This module assists applications that want to read numbered files in
16 sequence with very strict latency requirements. One area where this
17 happens in video streaming applications that want to read one file per
18 frame.
19 When you use this module, a number of helper processes is started that
21 speculatively open files and read a number of bytes to prime the file
22 system cache, so that later on when the real application's request
23 comes along, no disk access is necessary.
24 This module is stackable.
26
28 preopen:names = /pattern/
29 preopen:names specifies the file name pattern which should trigger
30 the preopen helpers to do their work. We assume that the files are
31 numbered incrementally. So if your file names are numbered
32 FRAME00000.frm FRAME00001.frm and so on you would list them as
33 preopen:names=/FRAME*.frm/
34 preopen:num_bytes = BYTES
36 Specifies the number of bytes the helpers should speculatively
37 read, defaults to 1.
38 preopen:helpers = NUM-PROCS
40 Number of forked helper processes, defaults to 1.
41 preopen:queuelen = NUM-FILES
43 Number of files that should be speculatively opened. Defaults to
44 the 10 subsequent files.
45
47 This man page is part of version 4.9.1 of the Samba suite.
48
50 The original Samba software and related utilities were created by
51 Andrew Tridgell. Samba is now developed by the Samba Team as an Open
52 Source project similar to the way the Linux kernel is developed.
53 The PREOPEN VFS module was created with contributions from Volker
55 Lendecke and the developers at IBM.
56Samba 4.9.1 05/11/2019 VFS_PREOPEN(8)