1VFS_READAHEAD(8)          System Administration tools         VFS_READAHEAD(8)
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NAME

6       vfs_readahead - pre-load the kernel buffer cache
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SYNOPSIS

9       vfs objects = readahead
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DESCRIPTION

12       This VFS module is part of the samba(7) suite.
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14       This vfs_readahead VFS module detects read requests at multiples of a
15       given offset (hex 0x80000 by default) and then tells the kernel via
16       either the readahead system call (on Linux) or the posix_fadvise system
17       call to pre-fetch this data into the buffer cache.
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19       This module is useful for Windows Vista clients reading data using the
20       Windows Explorer program, which asynchronously does multiple file read
21       requests at offset boundaries of 0x80000 bytes.
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23       The offset multiple used is given by the readahead:offset option, which
24       defaults to 0x80000.
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26       The size of the disk read operations performed by vfs_readahead is
27       determined by the readahead:length option. By default this is set to
28       the same value as the readahead:offset option and if not set explicitly
29       will use the current value of readahead:offset.
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31       This module is stackable.
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OPTIONS

34       readahead:offset = BYTES
35           The offset multiple that causes readahead to be requested of the
36           kernel buffer cache.
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38       readahead:length = BYTES
39           The number of bytes requested to be read into the kernel buffer
40           cache on each readahead call.
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42       The following suffixes may be applied to BYTES:
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44              •   K - BYTES is a number of kilobytes
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46              •   M - BYTES is a number of megabytes
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48              •   G - BYTES is a number of gigabytes
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EXAMPLES

51                [hypothetical]
52                vfs objects = readahead
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VERSION

55       This man page is part of version 4.17.5 of the Samba suite.
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AUTHOR

58       The original Samba software and related utilities were created by
59       Andrew Tridgell. Samba is now developed by the Samba Team as an Open
60       Source project similar to the way the Linux kernel is developed.
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64Samba 4.17.5                      01/26/2023                  VFS_READAHEAD(8)
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