The extended file system or ext was the first filesystem created specifically for the Linux operating system. It was designed by Rémy Card to overcome certain limitations of the Minix file system and originally competed with xiafs as its potential replacement. Both, however, were quickly supplanted by ext2 and then ext3. The Minix file system is the native file system of the Minix operating system. ... Xiafs was a file system for the operating system Linux which was conceived and developed by Frank Xia and was based on the Minix file system. ... The ext2 or second extended file system is a file system for the Linux kernel. ... The ext3 or third extended filesystem is a journalled file system that is coming into increasing use among users of the Linux operating system. ...
A special file is referenced by a major number, which identifies the device type, and a minor number, which identifies the unit.
The VFS is an indirection layer which handles the file oriented system calls and calls the necessary functions in the physical filesystem code to do the I/O. This indirection mechanism is frequently used in Unix-like operating systems to ease the integration and the use of several filesystem types [Kleiman 1986, Seltzer et al.
System V semantics are a bit more complex: if a directory has the setgid bit set, new files inherit the group id of the directory and subdirectories inherit the group id and the setgid bit; in the other case, files and subdirectories are created with the primary group id of the calling process.
Ext2filesystem is a powerful and extensible filesystem for Linux and it is the most successful filesystem in the Linux community.
The EXT2filesystem is built on the basis that the data held in files is kept in data blocks.
The system administrator may choose the optimal block size (from 1,024 to 4,096 bytes), while creating an ext2filesystem, For instance, a 1,024-block size is preferable when the average file length is smaller than a few thousand bytes because this leads to less internal fragmentation.