Sistemas de Arquivos
A filesystem is a means to organize data to be retained after a program terminates. Filesystems provide procedures to store, retrieve, and update data, as well as to manage the available space on the device(s) which contain it.
Linux has a few dozen filesystems available, each with their own advantages and disadvantages when considering a particular use case.
Flash memory filesystems
The following flash memory filesystems are designed to be used on embedded flash memory known as MTDs; they are not intended to be used for USB based flash drives, SD cards, or other types of removable flash block devices.
|Journalling Flash File System version 2.
|Yet Another Flash File System.
|A next generation, robust, high performance filesystem supporting CoW (Copy-on-write), compression, and encryption.
|A copy-on-write B-tree file system (btrfs) with advanced features.
|A memory and space sensitive compressed filesystem that supports random reading. It avoids the block device layer and usefulness in tiny embedded systems with very tight memory constraints.
|The enterprise cryptographic filesystem for Linux.
|A (U)EFI variable filesystem
|Extensible File Allocation Table (exFAT) filesystem by Microsoft, natively supported since Linux 5.7
|The default, GPL licensed journaling filesystem for many Linux distributions.
|A Flash-Friendly File System (F2FS) created by Samsung for the Linux kernel.
|The File Allocation Table (FAT) filesystem. Originally created for use with Microsoft Windows.
|Global File System 2: A shared disk filesystem. Typically used in compute clusters.
|Hierarchical File System (HFS). Originally created for use with the Macintosh System Software, later renamed to Mac OS (Classic).
|The successor to HFS, introduced in Mac OS 8.1 and default filesystem for Mac OS X until macOS 10.12 Sierra.
|A GPL licensed, 64-bit Journaled File System (JFS) developed by IBM.
|A log-structured file system implementation for the Linux kernel.
|Microsoft Windows' New Technology File System (NTFS) (Windows' default filesystem).
|Oracle Cluster File System version 2.
|The only union-like filesystem built-in to the Linux kernel.
|Version 3 of the ReiserFS filesystem. Scheduled for removal from the kernel in 2025.
|A compressed, read-only file system for Linux
|Universal Disk Format - needed for mounting some kind of .iso files
|The Unix File System (UFS) also called the Berkeley Fast File System.
|A GPL licensed, 64-bit journaling filesystem created by Silicon Graphics.
|A CDDL (non-GPL compatible) licensed, copy-on-write filesystem created by Sun Microsystems.
Virtual filesystems, also called pseudo filesystems, are for storing temporary data in memory while the system is running.
|Used for debugging purposes; primarily Linux kernel development.
|Used to output and change of system and process information.
|Used by the TPM BIOS character driver, AppArmor and IMA, an integrity provider.
|Used to output information about and to configure devices and drivers.
|Used to store files in memory (RAM).
|udev requires devtmpfs (Maintain a devtmpfs filesystem to mount at /dev) in the kernel.
|A distributed object store and filesystem designed to provide excellent performance, reliability, and scalability.
|A powerful network/cluster filesystem.
|A common Linux network file system protocol.
|A re-implementation of the SMB/CIFS networking protocol.
|File system for accessing FTP hosts based on FUSE.
|FUSE module to mount ISO filesystem images.
|A FUSE filesystem providing access to Media Transfer Protocol (MTP) devices.
|A FUSE filesystem for SMB shares.
|Implements FUSE to mount filesystems in user space.
|Mount SquashFS archives using FUSE.
Filesystems can be mounted in several ways:
- mount - The command used to mount filesystems. Requires administrative privileges or entries in /etc/fstab.
- /etc/fstab - Contains descriptive information about the filesystems the system can mount.
- Removable media - Mount on file demand.
- Udevil - A small auto-mount utility with little dependencies.
- AutoFS - Automatic mount on file access.
- Linux Sea, by Sven Vermeulen, chapter about filesystems
- Bitrot and atomic COWs: Inside “next-gen” filesystems (Ars Technica)
- A Study of Linux File System Evolution (PDF document from USENIX)