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vfs_readahead(8) [centos man page]

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 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. Samba 4.0 06/17/2014 VFS_READAHEAD(8)

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VFS_COMMIT(8)						    System Administration tools 					     VFS_COMMIT(8)

NAME
vfs_commit - flush dirty data at specified intervals SYNOPSIS
vfs objects = commit DESCRIPTION
This VFS module is part of the samba(7) suite. The vfs_commit VFS module keeps track of the amount of data written to a file and synchronizes it to disk when a specified amount accumulates. vfs_commit is useful in two circumstances. First, if you have very precious data, the impact of unexpected power loss can be minimized by a small commit:dthresh value. Secondly, write performance can be improved on some systems by flushing file data early and at regular intervals. This module is stackable. OPTIONS
commit:dthresh = BYTES Synchronize file data each time the specified number of bytes has been written. 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
Synchronize the file data on the [precious] share after every 512 kilobytes (524288 bytes) of data is written: [precious] path = /data/precious vfs objects = commit commit:dthresh = 512K CAVEATS
On some systems, the data synchronization performed by commit may reduce performance. 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. Samba 4.0 06/17/2014 VFS_COMMIT(8)
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