Are you an EPFL student looking for a semester project?
Work with us on data science and visualisation projects, and deploy your project as an app on top of Graph Search.
Concept
Files-11
Summary
Files-11 is the used in the RSX-11 and OpenVMS operating systems from Digital Equipment Corporation. It supports record-oriented I/O, remote network access, and . The original ODS-1 layer is a ; the ODS-2 version is a , with support for access control lists,.
Files-11 is similar to, but significantly more advanced than, the file systems used in previous Digital Equipment Corporation operating systems such as TOPS-20 and RSTS/E.
The native OpenVMS file system is descended from older DEC operating systems and is similar in many ways, both having been designed by Dave Cutler. A major difference is the layout of directories. These file systems all provided some form of rudimentary non-hierarchical directory structure, typically based on assigning one directory per user account. Under RSTS/E, each user account was represented by two numbers, a [project,programmer] pair, and had one associated directory. Special system files, such as program executables and the OS itself, were stored in the directory of a reserved system account.
While this was suitable for PDP-11 systems, which possessed limited permanent storage capacity, VAX systems with much larger hard drives required a more flexible method of file storage: hierarchical directory layout in particular, the most notable improvement in ODS-2.
"Files-11" is the general term for five separate file systems, known as on-disk structure (ODS) levels 1 through 5.
ODS-1 is the used by the RSX-11 OS, supported by older VMS systems for RSX compatibility, but never used to support VMS itself; it has been largely superseded by ODS-2 and ODS-5.
ODS-2 is the standard VMS file system, and remains the most common file system for system disks (the disk on which the operating system is installed).
Although seldom referred to by their ODS level designations, ODS-3 and ODS-4 are the Files-11 support for the CD-ROM ISO 9660 and High Sierra Format file systems, respectively.
ODS-5 is an extended version of ODS-2 available on Alpha and IA-64 platforms which adds support for case-preserving filenames with non-ASCII characters and improvements to the hierarchical directory support.
Official source
About this result
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.
Related courses (32)
ME-213: Programmation pour ingénieur
Mettre en pratique les bases de la programmation vues au semestre précédent. Développer un logiciel structuré. Méthode de debug d'un logiciel. Introduction à la programmation scientifique. Introductio
COM-490: Large-scale data science for real-world data
This hands-on course teaches the tools & methods used by data scientists, from researching solutions to scaling up
prototypes to Spark clusters. It exposes the students to the entire data science pipe
MATH-201: Analysis III
Calcul différentiel et intégral.
Eléments d'analyse complexe.
Related publications (29)
Related people (2)
Related concepts (5)
File system
In computing, a file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one large body of data with no way to tell where one piece of data stopped and the next began, or where any piece of data was located when it was time to retrieve it. By separating the data into pieces and giving each piece a name, the data are easily isolated and identified.
Comparison of operating systems
These tables provide a comparison of operating systems, of computer devices, as listing general and technical information for a number of widely used and currently available PC or handheld (including smartphone and tablet computer) operating systems. The article "Usage share of operating systems" provides a broader, and more general, comparison of operating systems that includes servers, mainframes and supercomputers.
Hard link
In computing, a hard link is a directory entry (in a directory-based ) that associates a name with a . Thus, each file must have at least one hard link. Creating additional hard links for a file makes the contents of that file accessible via additional paths (i.e., via different names or in different directories). This causes an alias effect: a process can open the file by any one of its paths and change its content. By contrast, a soft link or to a file is not a direct link to the data itself, but rather a reference to a hard link or another soft link.