VFS_READAHEAD(8) System Administration tools VFS_READAHEAD(8)

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

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.

The following suffixes may be applied to BYTES:

+o K - BYTES is a number of kilobytes

+o M - BYTES is a number of megabytes

+o G - BYTES is a number of gigabytes

EXAMPLES

[hypothetical]
vfs objects = readahead

VERSION

This man page is part of version 4.18.11 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.

Samba 4.18.11 03/13/2024 VFS_READAHEAD(8)