Misplaced Pages

QNX4FS

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.
(Redirected from Qnx4fs) File system for operating systems
This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.
Find sources: "QNX4FS" – news · newspapers · books · scholar · JSTOR (February 2024) (Learn how and when to remove this message)

QNX4FS is an extent-based file system used by the QNX4 and QNX6 operating systems.

As the file system uses soft updates, it remains consistent even after a power failure, without using journaling. Instead, the writes are carefully ordered and flushed to disk at appropriate intervals so that the on-disk structure always remains consistent, no matter if the operation is interrupted. However, unflushed changes to the file system are nevertheless lost, as the disk cache is typically stored in volatile memory.

Another notable property of this file system is that its actual metadata, like inode information and disk bitmaps, are accessible in the same way as any other file on the file system (as /.inodes and /.bitmap, respectively). This is consistent with QNX's (in fact, Plan 9 from Bell Labs's, or historically Unix's) philosophy that "everything is a file".

References

  1. "The QNX4 Filesystem". Mike Cramer's Garage. June 1, 2001.

External links

File systems
Disk and
non-rotating
Optical disc
Flash memory and SSD
host-side wear leveling
Distributed parallel
NAS
Specialized
Pseudo
Encrypted
Types
Features
Access control
Interfaces
Lists
Layouts
Stub icon

This computer science article is a stub. You can help Misplaced Pages by expanding it.

Categories: