Q283827
Sign in to saveext4 (fourth extended filesystem) is a journaling file system for Linux, developed as the successor to ext3.
Key facts
- File system.name
- ext4
- File system.full_name
- Fourth extended file system
- File system.developer
- Mingming Cao, Andreas Dilger, Alex Zhuravlev (Tomas), Dave Kleikamp, Theodore Ts'o, Eric Sandeen, Sam Naghshineh, others
- File system.introduction_os
- Linux 2.6.19
- File system.introduction_date
- 10 October 2006
- File system.preceded_by
- ext3
- File system.partition_id
- MBR / EBR. GPT Windows BDP. GPT Linux filesystem data. GPT /home partition. GPT /srv (server data) partition.
- File system.directory_struct
- Linked list, hashed B-tree
- File system.file_struct
- Extents / Bitmap
- File system.bad_blocks_struct
- Table
- File system.max_filename_size
- 255 bytes (fewer for multibyte character encodings such as Unicode)
- File system.max_files_no
- 4 billion (specified at filesystem creation time)
- File system.max_volume_size
- 1 EiB
- File system.max_file_size
- 16–256 TiB (for 4–64 KiB block size)
- File system.filename_character_set
- All characters and character sequences permitted, except for NULL ('\0'), '/', and the special file names "." and ".." which are reserved for indicating (respectively) current and parent directories.
- File system.dates_recorded
- Modification (mtime), data or attribute modification (ctime), access (atime), deletion (dtime), creation (crtime)
- File system.date_range
- 14 December 1901 – 10 May 2446
- File system.date_resolution
- Nanosecond
via Wikipedia infobox
Article
16 sectionsContents
- Adoption
- Features
- Limitations
- Delayed allocation and potential data loss
- Implementation
- Interoperability
- General Architecture
- Superblock
- Group Descriptor Table
- Block Bitmap
- Inode Bitmap
- Block Group Descriptors
- Flexible block groups
- See also
- References
- External links
ext4 (fourth extended filesystem) is a journaling file system for Linux, developed as the successor to ext3.
ext4 was initially a series of backward-compatible extensions to ext3, many of them originally developed by Cluster File Systems for the Lustre file system between 2003 and 2006, meant to extend storage limits and add other performance improvements. However, other Linux kernel developers opposed accepting extensions to ext3 for stability reasons, and proposed to fork the source code of ext3, rename it as ext4, and perform all the development there, without affecting existing ext3 users. This proposal was accepted, and on 28 June 2006, Theodore Ts'o, the ext3 maintainer, announced the new plan of development for ext4.