Indexed allocation centralizes the addresses of a file's data blocks in an index structure.
This supports direct access without requiring physically adjacent blocks.
Correct Answer: C. Each file block contains a pointer to the next block
Explanation:
Linked allocation forms a chain of blocks that may be scattered across the disk.
It avoids external fragmentation but provides poor direct access and pointer overhead.
Contiguous allocation records a starting block and length for a run of adjacent blocks.
It provides fast sequential and direct access but makes growth and external fragmentation difficult.
Correct Answer: A. A special file containing a pathname that refers to another file or directory
Explanation:
A symbolic link stores a textual path that the file system resolves when accessed.
It can cross file systems but may become dangling if the target is removed.
An acyclic graph allows an object to have multiple directory references without creating recursive cycles.
Reference counts or similar mechanisms help manage deletion of shared objects.
A tree directory organizes files hierarchically through parent and child directories.
Absolute and relative pathnames can identify objects at different levels.
Correct Answer: B. It gives each user a separate file namespace
Explanation:
A two-level structure associates a user file directory with each account under a master directory.
Different users can therefore use the same file name without conflict.
Correct Answer: A. All users and files share one namespace, causing name conflicts and poor organization
Explanation:
A single-level directory places every file in one directory and requires globally unique names.
It becomes inconvenient as the number of users and files grows.
Correct Answer: D. To coordinate concurrent access so processes do not perform conflicting file operations
Explanation:
File locks can provide shared-read or exclusive-write coordination among processes.
They help preserve consistency when several users or programs access the same file.
Correct Answer: C. State shared by open instances, such as file position, access mode, reference count, and metadata links
Explanation:
The open-file table records kernel state needed while files are actively open.
Process file descriptors refer to these entries rather than duplicating all underlying information.
Indexed access searches an index that maps keys or record numbers to data locations.
It combines fast lookup with the ability to traverse records in an indexed order.
Direct access computes or specifies the desired block or record position independently of previous accesses.
It is well suited to disk-based databases and large fixed-record files.
