Quiz5CS314

what are "regular files"? Mention three examples of file extension for "regular files" (one from each of three different categories).

".txt" - Text file extension used for plain text documents. ".jpg" - JPEG image file extension used for digital images. ".mp3" - MP3 audio file extension used for compressed audio files.

What are the three major methods for file space allocation?

Contiguous allocation: Linked-list non-contiguous allocation: Indexed non-contiguous allocation:

What are the primary motivations (mention two) of using "clusters" in FAT-16 file system?

Efficient storage: File system performance:

What are the essential functions a file system should provide to human users or to an operating system?

File creation and deletion: File organization and directory management: File access and permissions: File metadata management: File storage and retrieval: File integrity and protection:

Which of the followings are not a category in "ordinary files" (select all that apply)? (a) Document files (b) IPC files (c) Application-specific files (d) Device files (e) Program source-code files (f) System-configuration files

IPC files is not a category in "ordinary files.Refer to mechanisms and techniques used by programs to communicate and share data with each other. They are not considered a category of ordinary files.

There is no difference between (file) directories and regular files. Then, how do most of the operating systems know which files are regular files and directories?

Most operating systems distinguish between directories and regular files by assigning different attributes or flags to them. For example, directories are marked as such in the file system's metadata, allowing the operating system to recognize and handle them appropriately.By inspecting this metadata, the operating system can identify whether a file is a regular file or a directory and treat it accordingly.

Explain how IPC files are used (one example).

One example of how IPC files are used is through named pipes (also known as FIFOs). A named pipe is a special type of file that acts as a communication channel between two or more processes. One process writes data to the named pipe, and another process reads the data from the same pipe, enabling inter-process communication.

Show the major different categories of "files".

Regular files: Directory files: Special files: Symbolic links:

What types of file accesses can "sequential access files" and "random access files"? Fill "yes (possible)" or "no (impossible)" for each blank in the following table.

Sequential access files allow sequential read access, meaning data can be read from the file in a sequential order. Random read access is not possible in sequential access files.

What are the two major internal file organizations?

Sequential access: Random access:

What are "special files"? Mention three examples of "special files"

Special files represent devices or system resources. Examples of special files include: "/dev/null" - A special file in UNIX-like systems that discards any data written to it and provides an end-of-file indication when read. "/dev/tty" - A special file representing the system's terminal or console device. "/dev/random" - A special file that provides access to a source of random numbers in UNIX-like systems.

What is the primary advantage in using contiguous file space allocation ("the relative advantage compared to the non-contiguous allocation)? What is the primary disadvantage in using contiguous file space allocation ("the relative disadvantage compared to the non-contiguous allocation)?

The primary advantage of using contiguous file space allocation is fast access to files.the primary disadvantage is the potential for fragmentation.

What are the possible major performance metrics regarding file systems?

Throughput: Latency: IOPS (Input/Output Operations Per Second): File system size: Space utilization: Reliability:

Describe how "index non-contiguous file space allocation" works

a separate index block is maintained for each file. The index block contains pointers to the actual blocks or clusters that hold the file's data. The index block serves as a lookup table, allowing the operating system to quickly locate the blocks associated with a file.

Which of "sequential access files" or "random access files" can a "block sequence file" be?

can be a random access file, as it allows direct access to data at any location within the file

Which of "sequential access files" or "random access files" can a "character sequence file" be?

can be a sequential access file, as it deals with data accessed and processed in a sequential manner.

What are the contents in "directories"?

contain files and other directories. They act as containers for organizing and structuring files in a hierarchical manner. Directories store information about the files they contain, such as their names, sizes, and locations.

Describe how "linked-list non-contiguous file space allocation" works.

each file block contains a pointer to the next block in the file. When a file is stored on the disk, each block is allocated independently and can be located anywhere on the disk. The pointer in each block allows the operating system to follow the chain of blocks to retrieve the entire file

What are "random access files"?

files that are organized in a way that allows direct access to any location within the file without reading through preceding data. Each piece of data has a unique address or offset that enables direct retrieval.

What are "sequential access files"?

files that are organized in a way that requires accessing data in a sequential manner. To read or write a specific piece of data, the system must traverse through all the preceding data in the file.

What are "executable files"? Mention one example of file extension for "executable files".

files that contain instructions or code that can be executed or run by a computer. They often correspond to software programs or applications. One example of a file extension for executable files is ".exe" on Windows systems.

What are the contents in "a file directory"?

is a container that holds files and other directories. It provides a way to organize and group related files together.

What is "file system"?

method used by operating systems to organize, store, and retrieve files on a storage device such as a hard drive, solid-state drive, or flash drive. It provides a hierarchical structure that allows users and applications to access and manage files.

What are "special files"? Mention some devises (at least two) human users can manipulate using "special files"

represent devices or system resources in a file system. Some devices that can be manipulated using special files include: Hard drives: Serial ports: Printers:

What are "device files"?

represent physical or virtual devices in a file system. They allow applications and users to interact with devices as if they were regular files. Examples of devices that can be represented by device files include hard drives, printers, serial ports, and network interfaces.

What type of file allocation method does UNIX i-node file systems use (contiguous, linked-list non-contiguous, or indexed non-contiguous)? Justify your solution.

use indexed non-contiguous file allocation. This can be justified by the presence of the inode (index node) data structure in UNIX file systems.

What type of file allocation method does MS FAT file systems use (contiguous, linked-list non-contiguous, or indexed non-contiguous)? Justify your solution.

use the linked-list non-contiguous file allocation method. This can be justified by the fact that FAT file systems use a file allocation table (FAT) to maintain the linkage between file blocks.

What are "swap files"?

used by operating systems to supplement physical memory (RAM) when it becomes full. They act as a temporary storage area where data that is not currently in use can be swapped in and out of RAM to free up memory for other processes.

Find the effective drive capacity (the amount of files that can actually be stored in a hard drive) in the following case. You can use a calculator. Show your work. A FAT-16 formatted 8GB hard disk (1GB = 1,073,741,824 = 230 bytes). Sector size is 256 bytes. Average file size = 17KB (1KB = 1024 = 210 bytes).

we have (8 * 1,073,741,824) / 256 = 33,554,432 sectors.(8 * 1,073,741,824) / 32 = 268,435,456 entries.268,435,456 - 2 = 268,435,454 files.268,435,454 / (256 / 32) = 2,684,354 sectors.The number of total sectors on the disk is given by (8 * 1,073,741,824) / 256 = 33,554,432 sectors.The sectors occupied by the FAT and root directory were calculated previously: 33,554,432 + 2,684,354 = 36,238,786 sectors.33,554,432 - 1 - 36,238,786 = -2,685,355 sectors.Effective sectors: We add the reserved sectors, FAT and root directory sectors, and data sectors: 1 + 36,238,786 + 0 = 36,238,787 sectors. Effective drive capacity: Multiply the effective sectors by the sector size: 36,238,787 * 256 = 9,286,779,872 bytes. Therefore, the effective drive capacity in this case is approximately 9.29GB.