vfs_readahead

Name

vfs_readahead — pre-load the kernel buffer cache

Synopsis

vfs objects = readahead

DESCRIPTION

This VFS module is part of the + samba(7) suite.

This vfs_readahead VFS module detects + read requests at multiples of a given offset (hex 0x80000 by + default) and then tells the kernel via either the readahead + system call (on Linux) or the posix_fadvise system call to + pre-fetch this data into the buffer cache.

This module is useful for Windows Vista clients reading + data using the Windows Explorer program, which asynchronously + does multiple file read requests at offset boundaries of 0x80000 + bytes.

The offset multiple used is given by the readahead:offset + option, which defaults to 0x80000.

The size of the disk read operations performed + by vfs_readahead is determined by the + readahead:length option. By default this is set to the + same value as the readahead:offset option and if not + set explicitly will use the current value of + readahead:offset.

This module is stackable.

OPTIONS

The following suffixes may be applied to BYTES:

K - BYTES is a number of kilobytes
M - BYTES is a number of megabytes
G - BYTES is a number of gigabytes

readahead:offset = BYTES: The offset multiple that causes readahead to be + requested of the kernel buffer cache.
readahead:length = BYTES: The number of bytes requested to be + read into the kernel buffer cache on each + readahead call.

EXAMPLES

+	[hypothetical]
+	vfs objects = readahead
+

VERSION

This man page is correct for version 3.0.25 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.