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man pages section 8: System Administration Commands

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Updated: Thursday, June 13, 2019
 
 

vfs_preopen (8)

Name

vfs_preopen - Hide read latencies for applications reading numbered files

Synopsis

vfs objects = preopen

Description

System Administration tools                                     VFS_PREOPEN(8)



NAME
       vfs_preopen - Hide read latencies for applications reading numbered
       files

SYNOPSIS
       vfs objects = preopen

DESCRIPTION
       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.

OPTIONS
       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:names=/FRAME*.frm/

       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.

VERSION
       This man page is part of version 4.9.3 of the Samba suite.

AUTHOR
       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.



ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+-----------------------+
       |ATTRIBUTE TYPE |   ATTRIBUTE VALUE     |
       +---------------+-----------------------+
       |Availability   | service/network/samba |
       +---------------+-----------------------+
       |Stability      | Volatile              |
       +---------------+-----------------------+
NOTES
       This software was built from source available at
       https://github.com/oracle/solaris-userland.  The original community
       source was downloaded from
       https://download.samba.org/pub/samba/stable/samba-4.9.3.tar.gz

       Further information about this software can be found on the open source
       community website at http://www.samba.org/.



Samba 4.9.3                       01/24/2019                    VFS_PREOPEN(8)