Editing Universal Disk Format (section)

{{short description|Vendor-neutral file system, used in practice for DVDs and other optical discs}}
{{Use dmy dates|date=September 2019}}
{{Infobox filesystem
| name                    = UDF
| full_name               = Universal Disk Format
| developer               = [[International Organization for Standardization|ISO]]/[[International Electrotechnical Commission|IEC]], [[Ecma International]], [[Optical Storage Technology Association|OSTA]]
| introduction_os         = 
| introduction_date       = {{Start date and age|1995}}
| partition_id            = Not assigned but suggested:<ref>{{cite web|url=https://serverfault.com/a/829172|title=Serverfault answer for: What is the partition id / filesystem type for UDF?}}</ref><br />{{mono|[[Partition type#PID 07h|0x07]]}} ([[Master boot record|MBR]])<br />{{mono|[[Basic Data Partition|EBD0A0A2-B9E5-4433-87C0-68B6B72699C7]]}} ([[GUID Partition Table|GPT]])
| file_struct             = 
| bad_blocks_struct       = 
| max_filename_size       = 255 bytes (path 1023 bytes{{efn|name="note-43"|This restriction might be lifted in newer versions.}})
| max_files_no            = 
| max_volume_size         = 2 [[Tebibyte|TiB]] (with 512-byte sectors), 8 TiB (with 2 KiB sectors, like most optical discs), 16 TiB (with 4 KiB sectors){{efn|2<sup>32</sup> × ''block size''}}<ref>{{cite web |url=https://sites.google.com/site/udfintro/ |title=Wenguang's Introduction to Universal Disk Format (UDF) |at=Section 5.1 Highlight of the UDF Format |date=1 February 2009 |website=Google Sites |access-date=16 July 2014 }}</ref>
| max_file_size           = 16 [[Exbibyte|EiB]]
| filename_character_set  = Any 16-bit [[Unicode]] [[Code point]] excluding [[Byte order mark|U+FEFF]] and [[U+FFFE]]
| dates_recorded          = creation, archive, modification (mtime), attribute modification (ctime), access (atime)<!--double check-->
| date_range              = :24:00:00.000, 1 January 1 (UTC) {{spaced en dash}} 23:59:59.999, 31 December 9999 (UTC) <ref>[https://www.ecma-international.org/wp-content/uploads/ECMA-167_3rd_edition_june_1997.pdf ECMA 167 third edition, June 1997]</ref>
| date_resolution         =[[Microsecond]] 
| forks_streams           = Yes
| attributes              = Various
| file_system_permissions = POSIX
| compression             = No
| directory_struct        = 
| encryption              = 
| OS                      = Various
}}

'''Universal Disk Format''' ('''UDF''') is an [[open format|open]], vendor-neutral [[file system]] for [[computer data storage]] for a broad range of media. In practice, it has been most widely used for [[DVD]]s and newer [[optical disc]] formats, supplanting [[ISO 9660]]. Due to its design, it is very well suited to incremental updates on both [[Write once read many|write-once]] and re-writable [[Optical disc|optical media]]. UDF was developed and maintained by the [[Optical Storage Technology Association]] (OSTA).

In engineering terms, Universal Disk Format is a [[profile (engineering)|profile]] of the specifications known as ISO/IEC 13346 and ECMA-167.<ref name=ecma167>{{cite web |url = http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-167.pdf |title = ECMA-167 – Volume and File Structure for Write-Once and Rewritable Media using Non-Sequential Recording for Information Interchange}}</ref>