XFS_User_Guide/en-US/XFS-Background.xml - pub/scm/fs/xfs/xfsdocs-xml-dev - Git at Google

 <?xml version='1.0' encoding='utf-8' ?>
 <!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN" "http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd" [
 ]>
 <chapter id="xfs-background">
 	<title>XFS Background</title>
 	<section>
 		<title>Course Objectives</title>
 		<para>By the end of this course you will be able to:
 			<itemizedlist>
 			<listitem><para>Create and mount XFS filesystems</para></listitem>
 			<listitem><para>Understand how XFS
 				<itemizedlist>
 				<listitem><para>Creates and manages metadata</para></listitem>
 				<listitem><para>Allocates extents to files and manages free space</para></listitem>
 				<listitem><para>Provides extended attributes</para></listitem>
 				<listitem><para>Tracks filesystem quotas</para></listitem>
 				</itemizedlist>
 			</para></listitem>
 			<listitem><para>Backup and restore an XFS filesystem</para></listitem>
 			<listitem><para>Recover and repair XFS filesystems</para></listitem>
 			<listitem><para>Interpret on-disk and in-core XFS structures</para></listitem>
 			</itemizedlist>
 		</para>
 		<section>
 			<title>Day 1</title>
 			<formalpara>
 				<title>Theory</title>
 				<para>
 					<itemizedlist>
 						<listitem><para>Background and History</para></listitem>
 						<listitem><para>XFS Build</para></listitem>
 						<listitem><para>XFS Overview</para></listitem>
 						<listitem><para>Creating Filesystems</para></listitem>
 						<listitem><para>Mounting Filesystems</para></listitem>
 						<listitem>
 							<para>
 								Allocators
 							</para>
 						</listitem>
 						<listitem>
 							<para>
 								Quotas
 							</para>
 						</listitem>
 						<listitem>
 							<para>
 								Extended Attributes
 							</para>
 						</listitem>
 					</itemizedlist>
 				</para>
 			</formalpara>
 			<formalpara>
 				<title>Practise</title>
 				<para>
 					<itemizedlist>
 						<listitem>
 							<para>
 								XFS Build
 							</para>
 						</listitem>
 						<listitem>
 							<para>
 								Creating and Mounting XFS
 							</para>
 						</listitem>
 						<listitem>
 							<para>
 								Allocators
 							</para>
 						</listitem>
 						<listitem>
 							<para>
 								Quotas
 							</para>
 						</listitem>
 						<listitem>
 							<para>
 								Extended Attributes
 							</para>
 						</listitem>
 					</itemizedlist>
 				</para>
 			</formalpara>
 		</section>
 		<section>
 			<title>Day 2</title>
 			<formalpara>
 				<title>Theory</title>
 				<para>
 					<itemizedlist>
 						<listitem>
 							<para>
 								XFS Architecture and Internals
 							</para>
 						</listitem>
 						<listitem>
 							<para>
 								Q &amp; A
 							</para>
 						</listitem>
 					</itemizedlist>
 				</para>
 			</formalpara>
 			<formalpara>
 				<title>Practise</title>
 				<para>
 					<itemizedlist>
 						<listitem>
 							<para>
 								XFS On Disk Format
 							</para>
 						</listitem>
 						<listitem>
 							<para>
 								Q &amp; A
 							</para>
 						</listitem>
 					</itemizedlist>
 				</para>
 			</formalpara>
 		</section>
 		<section>
 			<title>Day 3</title>
 			<formalpara>
 				<title>Theory &amp; Practise</title>
 				<para>
 					<itemizedlist>
 						<listitem>
 							<para>
 								Repairing XFS Filesystems
 							</para>
 						</listitem>
 						<listitem>
 							<para>
 								XFS Triage
 							</para>
 						</listitem>
 						<listitem>
 							<para>
 								Monitoring
 							</para>
 						</listitem>
 					</itemizedlist>
 				</para>
 			</formalpara>
 		</section>
 		<section>
 			<title>Day 4</title>
 						<formalpara>
 				<title>Theory</title>
 				<para>
 					<itemizedlist>
 						<listitem>
 							<para>
 								Dump and Restore
 							</para>
 						</listitem>
 						<listitem>
 							<para>
 								XFS and Volume Managers
 							</para>
 						</listitem>

 					</itemizedlist>
 				</para>
 			</formalpara>
 			<formalpara>
 				<title>Practise</title>
 				<para>
 					<itemizedlist>
 						<listitem>
 							<para>
 								Dump and Restore
 							</para>
 						</listitem>
 					</itemizedlist>
 				</para>
 			</formalpara>
 		</section>
 	</section>
 	<section>
 		<title>A Brief History of XFS</title>
 		<para>
 			Original design was circulated within SGI in October 1993:
 		</para>
 		<para>
 			xFS: the extension of EFS
 		</para>
 		<itemizedlist>
 			<listitem>
 				<para>
 					"x" for to-be-determined (but the name stuck)
 				</para>
 			</listitem>
 			<listitem>
 				<para>
 					Large files: up to 9 ExaBytes (16TB on 32-bit systems).
 				</para>
 			</listitem>
 			<listitem>
 				<para>
 					Large filesystems: up to 18 ExaBytes (16TB on 32-bit systems).
 				</para>
 			</listitem>
 			<listitem>
 				<para>
 					Large number of inodes
 				</para>
 			</listitem>
 			<listitem>
 				<para>
 					Large directories
 				</para>
 			</listitem>
 			<listitem>
 				<para>
 					Large I/O
 				</para>
 			</listitem>
 			<listitem>
 				<para>
 					Parallelized access via allocation groups
 				</para>
 			</listitem>
 			<listitem>
 				<para>
 					Balanced tree (btree) algorithms for searching large lists
 				</para>
 			</listitem>
 			<listitem>
 				<para>
 					Asynchronous metadata transaction logging for quick recovery
 				</para>
 			</listitem>
 			<listitem>
 				<para>
 					Delayed allocation to improve data contiguity and performance
 				</para>
 			</listitem>
 			<listitem>
 				<para>
 					Extended attributes (such as Access Control Lists)
 				</para>
 			</listitem>
 			<listitem>
 				<para>
 					Extent based allocation (including unwritten extents)
 				</para>
 			</listitem>
 			<listitem>
 				<para>
 					Variable allocation block sizes
 				</para>
 			</listitem>
 			<listitem>
 				<para>
 					Direct I/O
 				</para>
 			</listitem>
 		</itemizedlist>
 		<para>
 			First released in IRIX 5.3
 		</para>
 	</section>
 	<section>
 		<title>XFS on Linux</title>
 		<para>
 			Port to Linux began in 1999 against 2.3.40
 		</para>
 		<para>
 			Accepted into mainline
 		</para>
 		<itemizedlist>
 			<listitem>
 				<para>
 					2.5 kernel (2002)
 				</para>
 				<para>
 					2.4 kernel (2004)
 				</para>
 			</listitem>
 		</itemizedlist>
 		<para>
 			SGI still has engineering resources for XFS
 		</para>
 		<para>
 			A significant number of contributors in the community
 		</para>
 		<itemizedlist>
 			<listitem>
 				<para>
 					Many (but not all) are ex-SGI employees
 				</para>
 			</listitem>
 		</itemizedlist>
 	</section>
 	<section>
 		<title>Who is using XFS</title>
 		<para>
 			XFS is included in a number of distributions:
 		</para>
 		<itemizedlist>
 			<listitem>
 				<para>
 					<ulink url="http://xfs.org/index.php/Linux_Distributions_shipping_XFS" />
 				</para>
 			</listitem>
 			<listitem>
 				<para>
 					List is not always current, but it gives an indication of the spread of users
 				</para>
 			</listitem>
 		</itemizedlist>
 		<para>
 			Some of the companies using XFS:
 		</para>
 		<itemizedlist>
 			<listitem>
 				<para>
 					<ulink url="http://xfs.org/index.php/XFS_Companies" />
 				</para>
 			</listitem>
 		</itemizedlist>
 	</section>
 	<section>
 		<title>XFS Distributions – kernelspace</title>
 		<para>
 			Top of tree (tot) XFS on oss.sgi.com
 		</para>
 		<itemizedlist>
 			<listitem>
 				<para>
 					Main SGI release tree is on oss.sgi.com
 				</para>
 				<itemizedlist>
 					<listitem>
 						<para>
 							<ulink url="http://oss.sgi.com/cgi-bin/gitweb.cgi?p=xfs/xfs.git" />
 						</para>
 					</listitem>
 				</itemizedlist>
 			</listitem>
 			<listitem>
 				<para>
 					Development tree on kernel.org
 				</para>
 				<itemizedlist>
 					<listitem>
 						<para>
 							<ulink url="http://git.kernel.org/?p=fs/xfs/xfs.git" />
 						</para>
 					</listitem>
 				</itemizedlist>
 			</listitem>
 		</itemizedlist>
 		<para>
 			Changes routinely pushed to 2.6 mainline kernel updates
 		</para>
 	</section>
 	<section>
 		<title>XFS Distributions - userspace</title>
 		<para>
 			A large amount of common code between kernel and user-space
 		</para>
 		<itemizedlist>
 			<listitem>
 				<para>
 					This is how xfs_repair understands the on-disk format
 				</para>
 			</listitem>
 		</itemizedlist>
 		<para>
 			User-space commands in a different code base
 		</para>
 		<para>
 			 Main upstream development is in SGI git tree on oss.sgi.com
 		</para>
 		<itemizedlist>
 			<listitem>
 				<para>
 					Main utilities: <ulink url="http://oss.sgi.com/cgi-bin/gitweb.cgi?p=xfs/cmds/xfsprogs.git" />
 				</para>
 			</listitem>
 		</itemizedlist>
 		<itemizedlist>
 			<listitem>
 				<para>
 					Dump/Restore: <ulink url="http://oss.sgi.com/cgi-bin/gitweb.cgi?p=xfs/cmds/xfsdump.git" />
 				</para>
 			</listitem>
 		</itemizedlist>
 		<itemizedlist>
 			<listitem>
 				<para>
 					QA Suite: <ulink url="http://oss.sgi.com/cgi-bin/gitweb.cgi?p=xfs/cmds/xfstests.git" />
 				</para>
 			</listitem>
 		</itemizedlist>
 		<para>
 			kernel.org development repos routinely pulled to sgi:
 		</para>
 		<itemizedlist>
 			<listitem>
 				<para>
 					Main utilities: <ulink url="http://git.kernel.org/?p=fs/xfs/xfsprogs-dev.git" />
 				</para>
 			</listitem>
 		</itemizedlist>
 		<itemizedlist>
 			<listitem>
 				<para>
 					Dump/Restore: <ulink url="http://git.kernel.org/?p=fs/xfs/xfsdump-dev.git" />
 				</para>
 			</listitem>
 		</itemizedlist>
 		<itemizedlist>
 			<listitem>
 				<para>
 					QA Suite: <ulink url="http://git.kernel.org/?p=fs/xfs/xfstests-dev.git" />
 				</para>
 			</listitem>
 		</itemizedlist>
 		<para>
 			Packaged as
 		</para>
 		<itemizedlist>
 			<listitem>
 				<para>
 					xfsprogs
 				</para>
 			</listitem>
 			<listitem>
 				<para>
 					xfsprogs-devel
 				</para>
 			</listitem>
 			<listitem>
 				<para>
 					xfsdump
 				</para>
 			</listitem>
 		</itemizedlist>
 		<note><para>The xfstests test suite is not yet packaged</para></note>
 	</section>
 	<section>
 		<title>IRIX vs Linux</title>
 		<para>Linux:</para>
 		<itemizedlist>
 		<listitem><para>Does not support V1 directories</para></listitem>
 		<listitem><para>Filesystem block size &lt;= PAGE_SIZE only</para></listitem>
 		</itemizedlist>
 		<para>IRIX:</para>
 		<itemizedlist>
 		<listitem><para>Does not support >512 byte sector sizes
 			<itemizedlist>
 			<listitem><para>MD RAID5</para></listitem>
 			</itemizedlist>
 		</para></listitem>
 		<listitem><para>Does not support write barriers</para></listitem>
 		<listitem><para>Does not support “noikeep” functionality</para></listitem>
 		</itemizedlist>
 	</section>
 </chapter>
	<?xml version='1.0' encoding='utf-8' ?>
	<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN" "http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd" [
	]>
	<chapter id="xfs-background">
	<title>XFS Background</title>
	<section>
	<title>Course Objectives</title>
	<para>By the end of this course you will be able to:
	<itemizedlist>
	<listitem><para>Create and mount XFS filesystems</para></listitem>
	<listitem><para>Understand how XFS
	<itemizedlist>
	<listitem><para>Creates and manages metadata</para></listitem>
	<listitem><para>Allocates extents to files and manages free space</para></listitem>
	<listitem><para>Provides extended attributes</para></listitem>
	<listitem><para>Tracks filesystem quotas</para></listitem>
	</itemizedlist>
	</para></listitem>
	<listitem><para>Backup and restore an XFS filesystem</para></listitem>
	<listitem><para>Recover and repair XFS filesystems</para></listitem>
	<listitem><para>Interpret on-disk and in-core XFS structures</para></listitem>
	</itemizedlist>
	</para>
	<section>
	<title>Day 1</title>
	<formalpara>
	<title>Theory</title>
	<para>
	<itemizedlist>
	<listitem><para>Background and History</para></listitem>
	<listitem><para>XFS Build</para></listitem>
	<listitem><para>XFS Overview</para></listitem>
	<listitem><para>Creating Filesystems</para></listitem>
	<listitem><para>Mounting Filesystems</para></listitem>
	<listitem>
	<para>
	Allocators
	</para>
	</listitem>
	<listitem>
	<para>
	Quotas
	</para>
	</listitem>
	<listitem>
	<para>
	Extended Attributes
	</para>
	</listitem>
	</itemizedlist>
	</para>
	</formalpara>
	<formalpara>
	<title>Practise</title>
	<para>
	<itemizedlist>
	<listitem>
	<para>
	XFS Build
	</para>
	</listitem>
	<listitem>
	<para>
	Creating and Mounting XFS
	</para>
	</listitem>
	<listitem>
	<para>
	Allocators
	</para>
	</listitem>
	<listitem>
	<para>
	Quotas
	</para>
	</listitem>
	<listitem>
	<para>
	Extended Attributes
	</para>
	</listitem>
	</itemizedlist>
	</para>
	</formalpara>
	</section>
	<section>
	<title>Day 2</title>
	<formalpara>
	<title>Theory</title>
	<para>
	<itemizedlist>
	<listitem>
	<para>
	XFS Architecture and Internals
	</para>
	</listitem>
	<listitem>
	<para>
	Q & A
	</para>
	</listitem>
	</itemizedlist>
	</para>
	</formalpara>
	<formalpara>
	<title>Practise</title>
	<para>
	<itemizedlist>
	<listitem>
	<para>
	XFS On Disk Format
	</para>
	</listitem>
	<listitem>
	<para>
	Q & A
	</para>
	</listitem>
	</itemizedlist>
	</para>
	</formalpara>
	</section>
	<section>
	<title>Day 3</title>
	<formalpara>
	<title>Theory & Practise</title>
	<para>
	<itemizedlist>
	<listitem>
	<para>
	Repairing XFS Filesystems
	</para>
	</listitem>
	<listitem>
	<para>
	XFS Triage
	</para>
	</listitem>
	<listitem>
	<para>
	Monitoring
	</para>
	</listitem>
	</itemizedlist>
	</para>
	</formalpara>
	</section>
	<section>
	<title>Day 4</title>
	<formalpara>
	<title>Theory</title>
	<para>
	<itemizedlist>
	<listitem>
	<para>
	Dump and Restore
	</para>
	</listitem>
	<listitem>
	<para>
	XFS and Volume Managers
	</para>
	</listitem>

	</itemizedlist>
	</para>
	</formalpara>
	<formalpara>
	<title>Practise</title>
	<para>
	<itemizedlist>
	<listitem>
	<para>
	Dump and Restore
	</para>
	</listitem>
	</itemizedlist>
	</para>
	</formalpara>
	</section>
	</section>
	<section>
	<title>A Brief History of XFS</title>
	<para>
	Original design was circulated within SGI in October 1993:
	</para>
	<para>
	xFS: the extension of EFS
	</para>
	<itemizedlist>
	<listitem>
	<para>
	"x" for to-be-determined (but the name stuck)
	</para>
	</listitem>
	<listitem>
	<para>
	Large files: up to 9 ExaBytes (16TB on 32-bit systems).
	</para>
	</listitem>
	<listitem>
	<para>
	Large filesystems: up to 18 ExaBytes (16TB on 32-bit systems).
	</para>
	</listitem>
	<listitem>
	<para>
	Large number of inodes
	</para>
	</listitem>
	<listitem>
	<para>
	Large directories
	</para>
	</listitem>
	<listitem>
	<para>
	Large I/O
	</para>
	</listitem>
	<listitem>
	<para>
	Parallelized access via allocation groups
	</para>
	</listitem>
	<listitem>
	<para>
	Balanced tree (btree) algorithms for searching large lists
	</para>
	</listitem>
	<listitem>
	<para>
	Asynchronous metadata transaction logging for quick recovery
	</para>
	</listitem>
	<listitem>
	<para>
	Delayed allocation to improve data contiguity and performance
	</para>
	</listitem>
	<listitem>
	<para>
	Extended attributes (such as Access Control Lists)
	</para>
	</listitem>
	<listitem>
	<para>
	Extent based allocation (including unwritten extents)
	</para>
	</listitem>
	<listitem>
	<para>
	Variable allocation block sizes
	</para>
	</listitem>
	<listitem>
	<para>
	Direct I/O
	</para>
	</listitem>
	</itemizedlist>
	<para>
	First released in IRIX 5.3
	</para>
	</section>
	<section>
	<title>XFS on Linux</title>
	<para>
	Port to Linux began in 1999 against 2.3.40
	</para>
	<para>
	Accepted into mainline
	</para>
	<itemizedlist>
	<listitem>
	<para>
	2.5 kernel (2002)
	</para>
	<para>
	2.4 kernel (2004)
	</para>
	</listitem>
	</itemizedlist>
	<para>
	SGI still has engineering resources for XFS
	</para>
	<para>
	A significant number of contributors in the community
	</para>
	<itemizedlist>
	<listitem>
	<para>
	Many (but not all) are ex-SGI employees
	</para>
	</listitem>
	</itemizedlist>
	</section>
	<section>
	<title>Who is using XFS</title>
	<para>
	XFS is included in a number of distributions:
	</para>
	<itemizedlist>
	<listitem>
	<para>
	<ulink url="http://xfs.org/index.php/Linux_Distributions_shipping_XFS" />
	</para>
	</listitem>
	<listitem>
	<para>
	List is not always current, but it gives an indication of the spread of users
	</para>
	</listitem>
	</itemizedlist>
	<para>
	Some of the companies using XFS:
	</para>
	<itemizedlist>
	<listitem>
	<para>
	<ulink url="http://xfs.org/index.php/XFS_Companies" />
	</para>
	</listitem>
	</itemizedlist>
	</section>
	<section>
	<title>XFS Distributions – kernelspace</title>
	<para>
	Top of tree (tot) XFS on oss.sgi.com
	</para>
	<itemizedlist>
	<listitem>
	<para>
	Main SGI release tree is on oss.sgi.com
	</para>
	<itemizedlist>
	<listitem>
	<para>
	<ulink url="http://oss.sgi.com/cgi-bin/gitweb.cgi?p=xfs/xfs.git" />
	</para>
	</listitem>
	</itemizedlist>
	</listitem>
	<listitem>
	<para>
	Development tree on kernel.org
	</para>
	<itemizedlist>
	<listitem>
	<para>
	<ulink url="http://git.kernel.org/?p=fs/xfs/xfs.git" />
	</para>
	</listitem>
	</itemizedlist>
	</listitem>
	</itemizedlist>
	<para>
	Changes routinely pushed to 2.6 mainline kernel updates
	</para>
	</section>
	<section>
	<title>XFS Distributions - userspace</title>
	<para>
	A large amount of common code between kernel and user-space
	</para>
	<itemizedlist>
	<listitem>
	<para>
	This is how xfs_repair understands the on-disk format
	</para>
	</listitem>
	</itemizedlist>
	<para>
	User-space commands in a different code base
	</para>
	<para>
	Main upstream development is in SGI git tree on oss.sgi.com
	</para>
	<itemizedlist>
	<listitem>
	<para>
	Main utilities: <ulink url="http://oss.sgi.com/cgi-bin/gitweb.cgi?p=xfs/cmds/xfsprogs.git" />
	</para>
	</listitem>
	</itemizedlist>
	<itemizedlist>
	<listitem>
	<para>
	Dump/Restore: <ulink url="http://oss.sgi.com/cgi-bin/gitweb.cgi?p=xfs/cmds/xfsdump.git" />
	</para>
	</listitem>
	</itemizedlist>
	<itemizedlist>
	<listitem>
	<para>
	QA Suite: <ulink url="http://oss.sgi.com/cgi-bin/gitweb.cgi?p=xfs/cmds/xfstests.git" />
	</para>
	</listitem>
	</itemizedlist>
	<para>
	kernel.org development repos routinely pulled to sgi:
	</para>
	<itemizedlist>
	<listitem>
	<para>
	Main utilities: <ulink url="http://git.kernel.org/?p=fs/xfs/xfsprogs-dev.git" />
	</para>
	</listitem>
	</itemizedlist>
	<itemizedlist>
	<listitem>
	<para>
	Dump/Restore: <ulink url="http://git.kernel.org/?p=fs/xfs/xfsdump-dev.git" />
	</para>
	</listitem>
	</itemizedlist>
	<itemizedlist>
	<listitem>
	<para>
	QA Suite: <ulink url="http://git.kernel.org/?p=fs/xfs/xfstests-dev.git" />
	</para>
	</listitem>
	</itemizedlist>
	<para>
	Packaged as
	</para>
	<itemizedlist>
	<listitem>
	<para>
	xfsprogs
	</para>
	</listitem>
	<listitem>
	<para>
	xfsprogs-devel
	</para>
	</listitem>
	<listitem>
	<para>
	xfsdump
	</para>
	</listitem>
	</itemizedlist>
	<note><para>The xfstests test suite is not yet packaged</para></note>
	</section>
	<section>
	<title>IRIX vs Linux</title>
	<para>Linux:</para>
	<itemizedlist>
	<listitem><para>Does not support V1 directories</para></listitem>
	<listitem><para>Filesystem block size <= PAGE_SIZE only</para></listitem>
	</itemizedlist>
	<para>IRIX:</para>
	<itemizedlist>
	<listitem><para>Does not support >512 byte sector sizes
	<itemizedlist>
	<listitem><para>MD RAID5</para></listitem>
	</itemizedlist>
	</para></listitem>
	<listitem><para>Does not support write barriers</para></listitem>
	<listitem><para>Does not support “noikeep” functionality</para></listitem>
	</itemizedlist>
	</section>
	</chapter>