About
In a file system, the basic persistent storage operations that permits to manage the file content are called:
- create - Creates a new file and open it
- write - Opens the file for write access (append - Appends the new data to the end of the file)
- read - Opens the file for read access
- delete - Delete the file
They are part made through file system request.
Unit
File System
The local/os file system performs all requests against the hard drive at the cluster size and holds them in memory in a cache.
Application
An application using the OS API can thereafter read file content from the File System Cache:
- at its own block level (such as fixed sized database records, ..)
- as if the sectors was contiguous
This operation is known as the scatter-gather scheme 1)
Lock
When the file system reads and writes file, file lock may be asked or taken in order to prevent data corruption.