Mount Rainier (technology)

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Mount Rainier describes a format for storing on optical storage media using packet writing and defect management with the aim of replacing floppy disks in the long term. The name comes from the Mount Rainier volcano in the United States of America .

Mount Rainier - MRW for short for Mount Rainier Read / Write - is only used on drives designed for this purpose. However, standard media such as CD-RW and DVD ± RW are used as data carriers .

functionality

A logic integrated in the drive ensures that an inserted medium looks like a physically empty area to the operating system that can be formatted and written to like a floppy disk or hard disk . There is therefore no specification for the file system to be used .

Internally, the drive works with the UDF file system. When formatting, some blocks are also reserved for defect management. Defective sectors are noted in a table in the lead-in and in a copy of this table in the lead-out . Formatting a new blank takes place in the background and thus only takes about a minute .

From the point of view of an operating system, a rewritable medium in an MRW drive is simply unused, error-free, block-addressable storage space that it can use in the usual way. Such an MRW medium can therefore also be formatted with FAT32 , NTFS or ext3 etc., although UDF is the recommended file format as it is best designed for working with optical storage media and is also the most widely used across operating systems. An MRW-formatted CD-RW with the UDF file system holds approximately 500  MiB of data.

Mount Rainier allows the use of a medium just a few seconds after it has been inserted: data can already be written to the medium during the "spin-up", even during the formatting phase. Before Mount Rainier, a rewritable optical medium first had to be formatted manually, which took a few minutes and had to be done from an application program designed for this purpose . Only after formatting was it possible to access the freshly formatted empty medium with other applications. MRW-formatted media can be read with special programs on non-MRW-compatible drives, but cannot be written to. One such program is, for example, EasyWrite Reader for Microsoft Windows .

An alternative to MRW drives is to manually format optical media with UDF version 1.5 or higher. A packet writing program can be used for this, or the operating system itself supports UDF version 1.5 or higher. The capabilities of Mount Rainier and UDF 1.5+ are partly similar.

Advantages of MRW compared to UDF 1.5+:

  • MRW allows fast formatting of the optical media in the background
  • MRW uses a smaller packet size compared to conventional packet writing programs (2  KiB compared to 64 KiB)
  • MRW allows any file system to be used on an optical medium
  • the defect management works independently of the operating system used

Advantages of UDF 1.5+ compared to MRW:

  • UDF does not require any special hardware, i.e. no MRW drive
  • UDF is more widely supported

Operating system support

Mount Rainier is fully implemented in Windows Vista . Linux support has existed since Linux kernel 2.6.2. AmigaOS  4 supports Mount Rainier since the first beta version in 2004.

Operating systems without Mount Rainier support (especially Windows XP and earlier versions) require drivers from third-party manufacturers in order to be able to use the MRW function of the drives. Most packet writing programs for Windows support MRW in addition to the conventional UDF function.

The marketing logo for Mount Rainier Compatible drives is the EasyWrite logo designed by Philips . It is intended to ensure that all products with this logo have been tested and meet the established quality standards.

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