vfs_readahead — pre-load the kernel buffer cache
vfs objects = readahead
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.
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
The offset multiple that causes readahead to be requested of the kernel buffer cache.
The number of bytes requested to be read into the kernel buffer cache on each readahead call.