Main Page

From btrfs Wiki
(Difference between revisions)
Jump to: navigation, search
m (foakley Jawbone Sunglasses:http://www.foakleys8888.com/oakley-jawbone-sunglasses-c-44.html)
m (Reverted edits by Roakleys8888 (talk) to last revision by Alankila)
Line 1: Line 1:
Those that reside in coastal regions are usually knowledgeable of the importance of a sea wall for preserving coastlines from both the ravages of ocean storms and the typical tidal activity of calm seas. Recently, there has been a fascinating response to the tourist beaches of Southern California, many that don't have sea walls as protection. Returning visitors are shocked to see how much the coastline has evolved since their previous visit from only a couple of years before. The sand dunes of the beach are molded as inexorably and capriciously as those of the Sahara desert [http://www.foakleys8888.com/ Replica Oakley Sunglasses]. Every morning, many of those beaches are actually attended by a dunes controller using a bulldozer, who re-sculpts the sand back to its original configuration [http://www.foakleys8888.com/ fake oakley sunglasses cheap sale]. It was instituted for the preservation of the beaches, together with all the beautiful beach front homes that are built along the coastline.
+
Btrfs is a new copy on write (CoW) filesystem for Linux aimed at implementing advanced features while focusing on fault tolerance, repair and easy administration. Jointly developed at Oracle, Red Hat, Fujitsu, Intel, SUSE, STRATO and many others, Btrfs is licensed under the GPL and open for contribution from anyone.
  
A powerful point was made about sea walls when the terrible Indian Ocean tsunami hit on December 26, 2004 and thousands of people lost their life along that coastline. What was not pointed out much on the news was the condition of the Pondicherry, which is actually a former French colonial enclave. The French had constructed a massive stone sea wall 300 years earlier, which left the area almost untouched by the 24 foot surge in the ocean level.
+
'''Btrfs is under heavy development, but every effort is being made to keep the filesystem stable and fast. Because of the speed of development, you should run the latest kernel you can (either the latest release kernel from kernel.org, or the latest -rc kernel.''' Please email the [[Btrfs mailing list]] if you have any problems or questions while using Btrfs.
  
 +
== Features ==
  
 +
Linux has a wealth of filesystems from which to choose, but we are facing a number of challenges with scaling to the large storage subsystems that are becoming common in today's data centers. Filesystems need to scale in their ability to address and manage large storage, and also in their ability to detect, repair and tolerate errors in the data stored on disk.
  
Sea walls have also been an essential part for hundreds of years, with regards to the development of nations. Just as flourishing cities in landlocked areas depend on the spot of the river nearby for transportation, coastal cities rely on a harbor to land ships. A natural harbor is really a relatively rare geological incidence. A few coastal cities find themselves at an economical and military pitfall since they don't have a deep enough harbor that's protected against the open sea. Sea walls have allowed areas to create their very own harbors, and fortify their natural geological structures.
+
'''The main Btrfs features available at the moment include:'''
  
The strongest and most resilient sea walls are made out of reinforced concrete. Nations such as Japan with extensive coastal regions have miles and miles of concrete seawalls protecting their coastlines. Forty three percent of Japans coastline is protected by a sea wall. It has protected the interior of Japan from the storms of the ocean and has guarded the integrity of its coastline from oceanic deterioration.
+
* Extent based file storage
 +
* 2^64 byte == 16 EiB maximum file size
 +
* Space-efficient packing of small files
 +
* Space-efficient indexed directories
 +
* Dynamic inode allocation
 +
* Writable snapshots, read-only snapshots
 +
* Subvolumes (separate internal filesystem roots)
 +
* Checksums on data and metadata (crc32c)
 +
* [[Compression]] (zlib and LZO)
 +
* Integrated multiple device support
 +
** File Striping, File Mirroring, File Striping+Mirroring, Striping with Single and Dual Parity implementations
 +
* SSD (Flash storage) awareness (TRIM/Discard for reporting free blocks for reuse) and optimizations (e.g. avoiding unnecessary seek optimizations, sending writes in clusters, even if they are from unrelated files. This results in larger write operations and faster write throughput)
 +
* Efficient [[Incremental Backup]]
 +
* Background scrub process for finding and fixing errors on files with redundant copies
 +
* Online filesystem defragmentation
 +
* [[btrfsck|Offline filesystem check]]
 +
* [[Conversion_from_Ext3|Conversion]] of existing ext3/4 file systems
 +
* [[Seed-device|Seed devices]]. Create a (readonly) filesystem that acts as a template to seed other Btrfs filesystems. The original filesystem and devices are included as a readonly starting point for the new filesystem. Using copy on write, all modifications are stored on different devices; the original is unchanged.
 +
* Subvolume-aware quota support
 +
* Send/receive of subvolume changes
 +
** Efficient incremental filesystem mirroring
  
In situations where a sea wall is needed but the erosive forces of the ocean are less serious, many other materials may be used. The interior of the San Francisco harbor is one example of this, since it is protected by the San Francisco peninsula but also has adequate size to feel the forces of the ocean [http://www.foakleys8888.com/ Oakley Sunglasses Sale], even in the immediate harbor area. One of the materials frequently used is vinyl. Vinyl, which is built in wall sections that are known as bulkheads [http://www.foakleys8888.com/ cheap fake oakleys], is a less expensive option in comparison to the concrete construction.
+
'''Additional features in development, or planned, include:'''
  
You can conform these bulkheads into three different types of sea walls described as vertical, curved or mound [http://www.foakleys8888.com/ foakley]. With the vertical sea wall being the simplest to build. They try to deflect wave energy away from the barrier. The curved walls will form a diffused structure that breaks up the wave energy more efficiently. This also directs the waves in a fashion that discourages splash over the walls. The curved wall also creates less disturbance. Permeable bulkheads do not completely block the water, but do dissipate and absorb the energy. With this being the least expensive in terms of cost.
+
* Very fast offline filesystem check
 +
* Object-level mirroring and striping
 +
* Alternative checksum algorithms
 +
* Online filesystem check
 +
* Other compression methods (snappy, lz4)
 +
* Hot data tracking and moving to faster devices (currently being pushed as a generic feature available through VFS)
 +
* Deduplication (online, offline)
  
These are a few of the ways that the lower cost vinyl walls may be used in nominal erosion situations.
+
== News ==
  
 +
<!--
 +
'''Linux in 3.9 (Apr 2013)'''
 +
-->
 +
''Coming in 3.10 (highlights or user visible changes)''
 +
* reduced size of metadata by so-called ''skinny extents'' [http://git.kernel.org/linus/3173a18f70554fe7880bb2d85c7da566e364eb3c]
 +
* enhanced syslog message format [http://permalink.gmane.org/gmane.comp.file-systems.btrfs/24330]
 +
* the mount option ''subvolrootid'' is deprecated
 +
* lots of stability improvements, removed <big>many</big> <small>BUG_ONs</small> <!-- a big thing! -->
 +
* qgroups are automatically created when quotas are enabled [http://git.kernel.org/linus/7708f029dca5f1b9e9d6ea01ab10cd83e4c74ff2]
 +
* qgroups are able to ''rescan'' current filesystem and sync the quota state with the existing subvolumes
 +
* enhanced ''send/recv '' format for multiplexing more data into one stream [http://git.kernel.org/linus/c2c71324ecb471c932bc1ff59e46ffcf82f274fc]
 +
* various unsorted code cleanups, minor performance updates
  
 +
''' Enterprise btrfs support (Feb 2012)'''
 +
* Since February 2012 there are two vendors who support btrfs in their distributions, [[Getting_started#Enterprise_distributions_with_btrfs_support|Oracle and SUSE]].
  
<br/>foakley antix black sunglasses ice iridium,http://www.foakleys8888.com/oakley-antix-black-sunglasses-ice-iridium-p-7283.html<br/> [http://www.foakleys8888.com/oakley-sunglasses-a001-p-6463.html foakley sunglasses A001]
+
Read about past releases in the [[Changelog]]
<br/> [http://www.foakleys8888.com/oakley-holbrook-black-sunglasses-p-7843.html foakley holbrook black sunglasses]
+
<br/> [http://www.foakleys8888.com/oakley-dispatch-ii-camo-sunglasses-tortoisebronze-p-7457.html foakley dispatch II camo sunglasses Tortoise/Bronze]
+
  
+
== Articles, presentations, podcasts ==
 +
* '''Article:''' [http://www.howtoforge.com/a-beginners-guide-to-btrfs A Beginner's Guide To Btrfs] (2012-11-26)
 +
* '''Article:''' [http://www.oracle.com/technetwork/articles/servers-storage-admin/advanced-btrfs-1734952.html How I Use the Advanced Capabilities of Btrfs] by Margaret Bierman with Lenz Grimmer (2012-08-11)
 +
* '''Article:''' [http://www.oracle.com/technetwork/articles/servers-storage-admin/gettingstarted-btrfs-1695246.html How I Got Started with the Btrfs File System for Oracle Linux] by Margaret Bierman with Lenz Grimmer (2012-07-11)
 +
* '''Paper:''' [http://domino.watson.ibm.com/library/CyberDig.nsf/1e4115aea78b6e7c85256b360066f0d4/6e1c5b6a1b6edd9885257a38006b6130!OpenDocument&Highlight=0,BTRFS draft] describing the overall concepts and architecture, to appear in ACM Transactions on Stroage 2013.
 +
* '''Article:''' [http://www.funtoo.org/wiki/BTRFS_Fun Btrfs Fun] Wiki page on funtoo.org (2012-05)
 +
* '''Video:''' [http://video.linux.com/videos/btrfs-filesystem-status-and-new-features Btrfs Filesystem: Status and New Features] by Chris Mason at the 2012 Linux Foundation Collaboration Summit (2012-04-05)
 +
* '''Article''' [http://static.usenix.org/publications/login/2012-02/openpdfs/Bacik.pdf Btrfs - The Swiss Army Knife Of Storage] by Josef Bacik (2012-02)
 +
* '''Video:''' [http://www.youtube.com/watch?v=hxWuaozpe2I I Can't Believe This is Butter! A tour of btrfs] by Avi Miller at linux.conf.au (2012-01-18)
 +
* '''Article:''' [http://lwn.net/Articles/465160/ A btrfs update at LinuxCon Europe] on lwn.net (2011-11-02)
 +
* '''Podcast:''' [http://feedproxy.google.com/~r/OracleLinux/~3/kRqpaCdTlLg/10491325_Btrfs_071311.mp3 Podcast with Chris Mason: Btrfs overview and status update] (2011-07-13)
 +
* '''Video:''' [http://vimeo.com/15325851 The Story So Far] by Josef Bacik at LinuxCon Brazil (2010-08-31)
 +
* '''Article:''' [http://www.linux.com/learn/tutorials/371623-weekend-project-get-started-with-btrfs Linux.com Weekend Project: Get Started with Btrfs] (2010-10-15)
 +
* '''Webcast:''' [https://event.on24.com/eventRegistration/EventLobbyServlet?target=registration.jsp&eventid=233161&sessionid=1&key=D0B1D3285FA444C5745C344A1C859CE0&partnerref=banner&sourcepage=register State of "Btrfs" File System for Linux by Chris Mason] (2010-08-26) [email registration and flash required]
 +
* '''Article:''' [http://lwn.net/Articles/342892/ Valerie Aurora: A short history of btrfs] (2009-07-22)
  
 +
== Documentation ==
  
Reality TV has swollen the ranks of celebrities from lists B through to Z to the point where it seems like every other week another almost has-been is busy trying to revive a faint career with a new fashion line [http://www.foakleys8888.com/ foakleys]. The lesson here seems to be stick with what you抮e good at [http://www.foakleys8888.com/ fake oakley sunglasses cheap sale], even if that抯 flashing your knickers at the paparazzi. Paris Hilton, we抮e looking at you. Read on for the worst celebrity fashion lines in all their shiny, tacky glory.
+
=== Guides and usage information ===
  
Paris Hilton
+
* [[Getting started]] — first steps, distributions with btrfs support
It seems Paris Hilton is a celebrity first and foremost for having money, and then working that fame to make even more. The kind of person who gets paid just for showing up at a party, Paris is sometimes more a marketable brand than a person. And what an unfortunate brand! Paris launched an exclusive line for Kitson Boutiques selling her particular brand of style ?mostly t-shirts screen printed with her face in gold lame. With lots of cheap, shiny dresses too, it has to be one of the most unattractive celebrity fashion lines on the market.
+
** [[Mount options]]
 +
* [[FAQ]] — About the btrfs project and filesystem
 +
* [[UseCases]] — Recipes for how to do stuff with btrfs
 +
* [[SysadminGuide]] — A more in-depth guide to btrfs' concepts and a bit of its internals, to answer all those "but what ''is'' a subvolume?" kind of questions.
 +
* [[Using Btrfs with Multiple Devices|Multiple devices]] – A guide to the RAID features of Btrfs
 +
* [[Conversion_from_Ext3|Conversion from Ext3 and Ext4]]
 +
* [[Problem FAQ]] — Commonly-encountered problems and solutions.
 +
** [[Gotchas]] — lists known bugs and issues, but not necessarily solutions.
  
 +
=== Project information ===
  
 +
* [[Changelog]] — history of changes in linux kernel wrt btrfs
 +
* [[Glossary]]
 +
* Contact information:
 +
** [[Btrfs mailing list]]
 +
** [http://en.wikipedia.org/wiki/Internet_Relay_Chat IRC] on freenode.net in the channel [irc://irc.freenode.net:6667/btrfs #btrfs]
 +
** Reporting bugs: see [[Problem_FAQ#How_do_I_report_bugs_and_issues.3F | the Bugzilla FAQ]] for reporting and finding bugs. Quick tip: use product ''File System'' and component ''btrfs''.
 +
* [[Project ideas]]
 +
* [[Cleanup ideas]]
  
Lauren Conrad
+
=== Using the built-in tools ===
Lauren Conrad, star of MTV reality show The Hills, actually has a pretty, laid-back California style. But her much anticipated line the Lauren Conrad Collection was a let-down. Lovely LC seemed to be going out of her way to 慸esign?as boring a basics collection as could be had ?an entire line made of plain and unflattering jersey cotton for some offensively high prices [http://www.foakleys8888.com/ Replica Oakley Sunglasses]. That hasn抰 stopped her from putting out another collection with US store Kohl抯 this autumn though, and unfortunately the second go-round is just as generic.
+
  
Lindsay Lohan
+
* [[Btrfs(command)|btrfs]] — main administration tool
Lindsay Lohan seems to feel that being a washed-up celebrity has-been with stringy blonde extensions gives her the right to nominate herself Marilyn Monroe抯 style representative on earth. No matter how hard she tries though she certainly can抰 match the lovely Monroe [http://www.foakleys8888.com/ fake oakley sunglasses], even if she creepily named her line of leggings ?126?after the screen siren抯 birthday. Lohan抯 line features leggings alone ?zipper leggings, faux leather leggings, sparkly leggings, shiny leggings. Hardly the most challenging item to design, they look like something a tween could customise with a glue gun, some cheap lycra and a portfolio of Miley Cyrus paparazzi snaps.
+
* [[Mkfs.btrfs|mkfs.btrfs]] — creating the filesystem
 +
* [[Btrfsck|btrfsck]] — repairing file systems
 +
* [[Restore|restore and find-root]] — utilities to find and restore data from an unmountable filesystem
 +
* [[Btrfs-convert|btrfs-convert]] — tool to convert in-place from ext2/3/4 filesystems to btrfs
  
Mischa Barton
+
=== Developer documentation ===
If La Lohan抯 leggings weren抰 enough of a capsule collection, someone actually thought they could make a quick buck from Mischa Barton抯 boho headbands. Starting at $50, Barton抯 hair accessories are over-priced, poorly finished and embellished in junk. The wilted hippy flowers stink of the desperation of someone who has been putting out forgettable, lack lustre performances since The O.C. ended three years ago.
+
  
The Jonas Brothers
+
* [[Code documentation]] — trees, source files, sample code for manipulating trees
Of all the things we though the Jonas Brothers could be doing ?pretending to play guitar and saving themselves for marriage ?sticking their names on a tween fashion line of ruffled denim skirts was not one of them. In spite of having no fashion experience and an average age of about 20, the family-friendly JoBros have their own fashion collection of mostly Disney-prep argyle sweaters, Polo shirts and pleated denim for thirteen year old girls at WalMart. It抯 a strange combination though of all the celebrities listed above, it抯 probably the most appropriately pitched and priced fashion line for the pop stars?fans [http://www.foakleys8888.com/ cheap fake oakleys].
+
* [[Data Structures]] — detailed on-disk data structures
 +
* [[Trees]] — detailed in-tree representation of files and directories
  
 +
* [[Btrfs design]] — design notes (possibly out of date in places)
 +
* [[Multiple Device Support]] — design notes
 +
* [[ENOSPC]] — Current ENOSPC design issues
  
 +
* [[Debugging Btrfs with GDB]]
 +
* [[Writing patch for btrfs]]
 +
* [[Unmerged Patches]] — patches with different features from btrfs mailing list
  
<br/>foakley antix black sunglasses ice iridium,http://www.foakleys8888.com/oakley-antix-black-sunglasses-ice-iridium-p-7283.html<br/> [http://www.foakleys8888.com/oakley-cwire-sunglasses-matte-blackwarm-grey-p-6234.html foakley c-wire sunglasses Matte Black/Warm Grey]
+
==== Source code download ====
<br/> [http://www.foakleys8888.com/oakley-jupiter-sunglasses-p-7960.html foakley jupiter sunglasses]
+
<br/> [http://www.foakleys8888.com/fake-oakleys-pit-boss-sunglasses-blue-p-9515.html fake oakleys pit boss sunglasses blue]
+
  
+
* [[Btrfs source repositories]]
 +
* [http://git.kernel.org/?p=linux/kernel/git/mason/linux-btrfs.git;a=tree;f=fs/btrfs;hb=HEAD Gitweb source viewer] of the main kernel repository
  
 +
== Benchmarking ==
  
Autumn is the time of year in which you can literally smell the changes. Leaves are burning, peanuts are roasting, and most people are just beginning to fill a hint of a chill in the air. More than smelling the changes that are coming you can see them. Leaves begin to take on brilliant hues and the colors are spectacular to watch and witness. This is the time of year that thoughts begin to turn to football, hiking, and the upcoming holidays (for there are quite a few on the horizon).  
+
* '''2012-10''' [http://www.ilsistemista.net/index.php/linux-a-unix/36-btrfs-mount-options-and-virtual-machines-an-in-depth-look.html BTRFS, mount options and virtual machines: an in-depth look] (Ilsistemista.net)
 
+
* '''2012-06''' [http://www.ilsistemista.net/index.php/linux-a-unix/34-btrfs-ext3-ext4-xfs-and-kvm-virtual-machine-a-host-side-filesystem-comparison.html BTRFS EXT3 EXT4 XFS and KVM virtual machine: a host-side filesystem comparison] (Ilsistemista.net)
Fall contains two primary holidays for many people. Those include Halloween and Thanksgiving. Keep these holidays in mind when planning your primary fall home decorating scheme and make small adjustments in order to accommodate the holidays [http://www.foakleys8888.com/ Oakley Sunglasses Sale]. Personally, I love the colors associated with autumn. The yellows, shades of gold, orange, and brown are favorites for my decorating taste. I always regret a little that this time of year is often overshadowed by Christmas as it approaches and the expectations of others that I decorate for Christmas almost immediately after celebrating Thanksgiving.
+
* '''2012-06''' [http://www.ilsistemista.net/index.php/linux-a-unix/33-btrfs-vs-ext3-vs-ext4-vs-xfs-performance-on-fedora-17.html BTRFS vs EXT3 vs EXT4 vs XFS performance on Fedora 17] (Ilsistemista.net)
 
+
* '''2012-05''' [http://www.phoronix.com/scan.php?page=article&item=linux_34_fs&num=1 XFS, Btrfs, EXT4 Battle It Out On Linux 3.4] (Phoronix.com)
 
+
* '''2012-05''' [http://cd34.com/blog/scalability/ext4-xfs-and-btrfs-benchmark-redux/ Ext4, XFS and Btrfs benchmark redux]
 
+
* '''2012-03''' [http://www.phoronix.com/scan.php?page=article&item=linux_btrfs_options&num=1 Testing Out The Btrfs Mount Options On Linux 3.2] (Phoronix.com)
For those who lack inspiration when it comes to home decorating for fall, keep the colors mentioned above in mind. One great theme to incorporate into the decorating process would be the theme of leaves. Leaves falling from the trees are one of the most common associations with this time of year and it is a great look to incorporate into your home [http://www.foakleys8888.com/ Cheap Oakley Sunglasses]. You can even find leaf garlands in fall shades if you are inclined to look for them. Leaves can also be incorporated into lovely centerpieces and floral arrangements to hallmark the season.
+
* '''2012-03''' [http://www.phoronix.com/scan.php?page=article&item=ubuntu_1204_fs&num=1 Ubuntu 12.04 LTS - Benchmarking All The Linux File-Systems] (Phoronix.com)
 
+
* '''2011-12''' [http://btrfs.boxacle.net Btrfs Performance Analysis]
Harvest is another common association with autumn [http://www.foakleys8888.com/ fake oakley sunglasses]. This is also rather easy to incorporate into most home decorating designs. Gourds make an excellent accent piece for this time of year and you can find real ones in almost any vegetable market along with many realistic imitation gourds. These can be used, much like or along with leaves, as part of centerpieces, in floral arrangements, in tabletop decorations, and even to hold place cards for large gatherings. They are incredibly versatile as well as colorful and make a great addition to any autumn home decorating venture [http://www.foakleys8888.com/ foakleys].  
+
* '''2011-11''' [http://www.phoronix.com/vr.php?view=16773 Testing The "Pretty Beefy" Btrfs Changes In Linux 3.2] (Phoronix.com)
 
+
* '''2011-10''' [http://www.ilsistemista.net/index.php/linux-a-unix/21-ext3-ext4-xfs-and-btrfs-filesystems-comparison-on-linux-kernel-300.html EXT3 vs EXT4 vs XFS vs BTRFS - filesystems comparison on Linux kernel 3.0.0] (Ilsistemista.net)
Pumpkins are essentially gourds but they have a special place all their own in the fall home decorating scheme. Pumpkins have a special association with both Halloween and Thanksgiving (pumpkin pie anyone) and should not be overlooked as an important tool for decoration. In addition they are just bright, colorful, and cheerful to have around the house. To avoid the stench of rotting pumpkins simply avoid carving them if you intend to keep them around for a little while. Those that are carved should be placed outside and only carved within days of the 'big day'.  
+
* '''2011-09''' [http://www.phoronix.com/scan.php?page=article&item=btrfs_linux31_ssd&num=1 Testing EXT4 & Btrfs On A Serial ATA 3.0 SSD] (Phoronix.com)
 
+
* '''2011-05''' [http://www.phoronix.com/scan.php?page=article&item=linux_2639_fs&num=1 Linux 2.6.39: XFS Speeds-Up, EXT4 &amp; Btrfs Unchanged] (Phoronix.com)
A great centerpiece idea in general for fall would include a large bowl, in outstanding fall colors such as a burnt orange or a shade of gold. For the first part of autumn you can fill the centerpiece with candies that are wrapped in fall colors. This is ideal for family munchies as well as trick or treaters that may find their way to your door on Halloween. Once this holiday has ended you can fill the bowl with colorful leaves and gourds to complete the look. This should carry you through Thanksgiving when it is time to begin thinking about Christmas decorations and wintertime rather than fall [http://www.foakleys8888.com/ cheap fake oakleys].  
+
* '''2011-03''' [http://www.phoronix.com/scan.php?page=article&item=btrfs_lzo_2638&num=1 Btrfs LZO Compression Performance] (Phoronix.com)
 
+
* '''2010-12''' [http://www.phoronix.com/scan.php?page=article&item=btrfs_space_cache&num=1 Benchmarks Of The Btrfs Space Cache Option] (Phoronix.com) Comparing the performance of Btrfs using the default mount options, using the space_cache mount option, using the compress mount option for Btrfs file compression, and lastly using both the space_cache and compression mount options to benefit from the free space caching and Zlib compression.
Whether you adore fall like I do or dread its appearance each year for whatever reason there is little denying that fall is ripe with decorating ideas and ideals. Take the time to look around your local craft stores and see where inspiration strikes. It is never too early or too late in the year to begin thinking about what you are going to do for your home decorating plan in the seasons to come.
+
* '''2010''' [http://www.mayrhofer.eu.org/ssd-linux-benchmark SSD Linux benchmarking: Comparing filesystems and encryption method]
 
+
* '''2010-11''' [http://www.ilsistemista.net/index.php/linux-a-unix/6-linux-filesystems-benchmarked-ext3-vs-ext4-vs-xfs-vs-btrfs.html EXT3 vs EXT4 vs XFS vs BTRFS linux filesystems benchmark] (Ilsistemista.net)
 
+
* '''2010-11''' [http://www.phoronix.com/scan.php?page=article&item=linux_2637_ext4btrfs&num=1 Phoronix: The Linux 2.6.37 Kernel With EXT4 &amp; Btrfs] (Phoronix.com) Comparison between Btrfs and Ext4.
 
+
* '''2010-10''' [http://www.linux-mag.com/id/7876 One Billion Files] Btrfs performs well in comparison to other filesystems, when there are a billion files in the filesystem.
<br/>foakley antix black sunglasses ice iridium,http://www.foakleys8888.com/oakley-antix-black-sunglasses-ice-iridium-p-7283.html<br/> [http://www.foakleys8888.com/oakley-x-squared-sunglasses-blackice-iridium-p-9521.html foakley x squared sunglasses black/ice iridium]
+
* '''2009-05''' [http://www.phoronix.com/scan.php?page=article&item=btrfs_ssd_mode&num=1 Phoronix Test With SSD Mode] (Phoronix.com) This test show that btrfs is slower with ssd option activated. Ssd code has been updated during 2.6.30-rc and is expected to be faster.
<br/> [http://www.foakleys8888.com/fake-oakleys-jawbone-navy-p-7933.html fake oakleys jawbone navy]
+
* '''2009-04''' [http://www.phoronix.com/scan.php?page=article&item=btrfs_benchmarks&num=1 Phoronix Performance Test on Fedora 11 Preview] (Phoronix.com) The phoronix workload is mostly CPU based, but they do have a few filesystem benchmarks. Btrfs performs well, but you can see the checksumming and metadata duplication show up on their single disk streaming write workload. dbench in general measures lots of different caching effects, and is not a great measure of everyday performance.
<br/> [http://www.foakleys8888.com/foakley-oil-rig-brown-p-8105.html foakley oil rig brown]
+
* '''2008-10''' [http://btrfs.boxacle.net Btrfs performance analysis by Steven Pratt and IBM] The benchmarks from IBM demonstrate some bottlenecks we have in the extent recording on large workloads. We're working on fixes for these.
 +
* '''2008-04''' [[Multi-device Benchmarks]]

Revision as of 10:22, 3 June 2013

Btrfs is a new copy on write (CoW) filesystem for Linux aimed at implementing advanced features while focusing on fault tolerance, repair and easy administration. Jointly developed at Oracle, Red Hat, Fujitsu, Intel, SUSE, STRATO and many others, Btrfs is licensed under the GPL and open for contribution from anyone.

Btrfs is under heavy development, but every effort is being made to keep the filesystem stable and fast. Because of the speed of development, you should run the latest kernel you can (either the latest release kernel from kernel.org, or the latest -rc kernel. Please email the Btrfs mailing list if you have any problems or questions while using Btrfs.

Contents

Features

Linux has a wealth of filesystems from which to choose, but we are facing a number of challenges with scaling to the large storage subsystems that are becoming common in today's data centers. Filesystems need to scale in their ability to address and manage large storage, and also in their ability to detect, repair and tolerate errors in the data stored on disk.

The main Btrfs features available at the moment include:

  • Extent based file storage
  • 2^64 byte == 16 EiB maximum file size
  • Space-efficient packing of small files
  • Space-efficient indexed directories
  • Dynamic inode allocation
  • Writable snapshots, read-only snapshots
  • Subvolumes (separate internal filesystem roots)
  • Checksums on data and metadata (crc32c)
  • Compression (zlib and LZO)
  • Integrated multiple device support
    • File Striping, File Mirroring, File Striping+Mirroring, Striping with Single and Dual Parity implementations
  • SSD (Flash storage) awareness (TRIM/Discard for reporting free blocks for reuse) and optimizations (e.g. avoiding unnecessary seek optimizations, sending writes in clusters, even if they are from unrelated files. This results in larger write operations and faster write throughput)
  • Efficient Incremental Backup
  • Background scrub process for finding and fixing errors on files with redundant copies
  • Online filesystem defragmentation
  • Offline filesystem check
  • Conversion of existing ext3/4 file systems
  • Seed devices. Create a (readonly) filesystem that acts as a template to seed other Btrfs filesystems. The original filesystem and devices are included as a readonly starting point for the new filesystem. Using copy on write, all modifications are stored on different devices; the original is unchanged.
  • Subvolume-aware quota support
  • Send/receive of subvolume changes
    • Efficient incremental filesystem mirroring

Additional features in development, or planned, include:

  • Very fast offline filesystem check
  • Object-level mirroring and striping
  • Alternative checksum algorithms
  • Online filesystem check
  • Other compression methods (snappy, lz4)
  • Hot data tracking and moving to faster devices (currently being pushed as a generic feature available through VFS)
  • Deduplication (online, offline)

News

Coming in 3.10 (highlights or user visible changes)

  • reduced size of metadata by so-called skinny extents [1]
  • enhanced syslog message format [2]
  • the mount option subvolrootid is deprecated
  • lots of stability improvements, removed many BUG_ONs
  • qgroups are automatically created when quotas are enabled [3]
  • qgroups are able to rescan current filesystem and sync the quota state with the existing subvolumes
  • enhanced send/recv format for multiplexing more data into one stream [4]
  • various unsorted code cleanups, minor performance updates

Enterprise btrfs support (Feb 2012)

  • Since February 2012 there are two vendors who support btrfs in their distributions, Oracle and SUSE.

Read about past releases in the Changelog

Articles, presentations, podcasts

Documentation

Guides and usage information

Project information

Using the built-in tools

  • btrfs — main administration tool
  • mkfs.btrfs — creating the filesystem
  • btrfsck — repairing file systems
  • restore and find-root — utilities to find and restore data from an unmountable filesystem
  • btrfs-convert — tool to convert in-place from ext2/3/4 filesystems to btrfs

Developer documentation

  • Code documentation — trees, source files, sample code for manipulating trees
  • Data Structures — detailed on-disk data structures
  • Trees — detailed in-tree representation of files and directories

Source code download

Benchmarking

Personal tools