Packet writing (or incremental packet writing, IPW) is an
optical disc recording technology used to allow write-once and rewritable
CD and
DVD media to be used in a similar manner to a
floppy disk
A floppy disk or floppy diskette (casually referred to as a floppy, or a diskette) is an obsolescent type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined ...
from within the
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common daemon (computing), services for computer programs.
Time-sharing operating systems scheduler (computing), schedule tasks for ef ...
.
Details
Packet writing allows users to create, modify, and delete files and directories on demand without the need to ''
burn
A burn is an injury to skin, or other tissues, caused by heat, cold, electricity, chemicals, friction, or ultraviolet radiation (like sunburn). Most burns are due to heat from hot liquids (called scalding), solids, or fire. Burns occur ma ...
'' a whole disc. Packet writing technology achieves this by writing data in incremental blocks rather than in a single block.
Deleting files and directories of a
CD-R using packet writing technology does not recover the space occupied by these objects but, rather, they are simply marked as being deleted (making them effectively ''hidden''). Similarly, changes to files cause new instances to be created instead of replacing the original files. Because of this, the available space on a non-rewritable medium using packet writing technology will decrease every time its content is modified.
The most common file system for packet writing systems is
UDF.
Due to the characteristics of optical rewritable media such as
CD-RWs and
DVD-RWs, the ability of data sectors to hold their contents diminishes when changing them frequently (since re-crystallized alloy de-crystallizes). To cope with this the packet writing system can remap bad sectors with good sectors as required. These bad sectors cannot be recovered by formatting the media.
[''"PC Hardware in a Nutshell: A Desktop Quick Reference"'' by Robert Bruce Thompson, Barbara Fritchman Thompson − Chapter 11 (starting page 340): CD writers]
/ref>
Software
Packet writing is most popularly implemented by Microsoft since Windows Vista
Windows Vista is a major release of the Windows NT operating system developed by Microsoft. It was the direct successor to Windows XP, which was released five years before, at the time being the longest time span between successive releases of ...
, where it is referred to as the Live File System.
Software implementing packet writing includes:
* Nero
* Drive Letter Access
* Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, whi ...
(since 2.6.8)
References
{{hardware-stub
Optical disc authoring
Optical computer storage media