The document discusses the Btrfs file system. It was jointly developed by Oracle, Red Hat, Intel and others as a new copy-on-write file system. Btrfs addresses limitations of other Linux file systems by adding features like snapshots, checksums, and defragmentation. It continues to be developed with goals of adding encryption, deduplication, and RAID 5/6 support in the future.

1. Head of Department
Prof. A.K. Solanki
Under the guidance of
Er. R.N. Verma
(Seminar-in-charge) Presented By:
Dinesh Chandra Gupta1/17

2. 1. Introduction
2. History
3. File system
4. Features
5. Design
6. Limitations
7. Future implements
8. Conclusion
9. References
CONTENTS
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3. 1. Jointly developed by Oracle, Red Hat, Intel and many
others.
2. Btrfs is a new copy on write(cow) file system.
3. The max no. of file is 2^64 and max file length is 255
character.
4. Btrfs is intended to address the lack of
snapshots, checksums in Linux file system.
5. Btrfs does allow for Defragmentation.
INTRODUCTION
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4. 1. Btrfs was proposed by IBM researcher Ohad Rodeh in
2007.
2. Btrfs 1.0 was released in 2008 as a trial version.
3. Btrfs was accepted in Linux kernel as of 2.6.29 in 2009.
4. In 2011 defragmentation features were announced for
the Linux 3.0 kernel version.
5. In 2012 Btrfs 3.0 was released.
6. Now Oracle,Red Hat,Intel and others are working more
in Btrfs.
HISTORY
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5. 1. a file system is used to control how data is
stored and retrieved.
2. Linux supports 140 file system.
3. Three popular file systems are
EXT4[17],ZFS[5],and BTRFS[3].
File System
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6. 1. Incremental backup
2. defragmentation
3. Online volume growth and shrinking
4. Subvolumes
5. Snapshots
6. File cloning
7. Online filesystem check
FEATURES
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7. Cloning of B-Tree
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8. -Every leaf and node begins with header
//Node :
struct btrfs_node {
struct btrfs_header header ;
struct btrfs_key_ptr ptrs [ ] ;
}
// Leaf :
struct btrfs_leaf {
struct btrfs_header header ;
struct btrfs_item items [ ] ;
}
DESIGN
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9. Leaf structure in Btrfs
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10. 10/17

11. COMPARISON WITH OTHER FILE SYSTEM
(Data organization in old-school filesystems)
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12. (Data organization in Btrfs)
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13. 1. Transactions
(a) Btrfs supports limited transactions without
Atomicity-Consistency-Isolation-Durability
semantics.
(b) Only one transaction may run at a time which
is not atomic wrt storage.
2. Checking and recovery
LIMITATIONS
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14. 1. Encryption
2. Data Deduplication
3. Ability to handle swap
4. Parity Based RAID(RAID5 and RAID6)
Future Development
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15. Btrfs provides few very unique and interesting
features but is still under heavy development
efforts and is in experimental state.
Although a very feature enrich file system but is
still very young to be used in a real production
environment. Also Btrfs is maturing into a stable
high performance file system. Worth keeping a
close watch on development.
Conclusion
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16. 1. “Ohad Rodeh”, Research paper on "B-
trees, Shadowing, and Clones" , InternetNews.com
oracle in July 2008.
2. “Cerner, Sean Michael” ,"A Better File System For
Linux“, InternetNews.com, Archived from the original
on 24 June 2012,Retrieved 2008-10-30.
3. “MACEDONIA,M.R.” ,“B-tree file
system”, IEEECommune. Magazine , vol. 47 pp. S30-
S38 , Mar 2007.
4. “Brown, Eric”, "Linux 3.0 scrubs up Btrfs, gets more
Xen",Linux devices (eWeek),Archived from the original
on 2013-01-27,Retrieved 8 November 2011.
References
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17. QUERIES ?
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