GATE CS File Systems questions

A disk of size $512 \text{ M}$ bytes is divided into blocks of $64 \text{ K}$ bytes. A file is stored in the disk using linked allocation. In linked allocation, each data block reserves $4$ bytes to store the pointer to the next data block. The link part of the last data block contains a NULL pointer (also of $4$ bytes). Suppose a file of …

Consider two files systems $\text{A}$ and $\text{B}$, that use contiguous allocation and linked allocation, respectively. A file of size $100$ blocks is already stored in $\text{A}$ and also in $\text{B}$. Now, consider inserting a new block in the middle of the file (between $50^{th}$ and $51^{st}$ block), whose data is already available in …

Consider a linear list based directory implementation in a file system. Each directory is a list of nodes, where each node contains the file name along with the file metadata, such as the list of pointers to the data blocks. Consider a given directory $\textsf{foo}$. Which of the following operations will necessarily require a full scan of $\textsf{foo}$ …

The index node (inode) of a Unix -like file system has $12$ direct, one single-indirect and one double-indirect pointers. The disk block size is $4$ kB, and the disk block address is $32$-bits long. The maximum possible file size is (rounded off to $1$ decimal place) ____ GB

In a file allocation system, which of the following allocation scheme(s) can be used if no external fragmentation is allowed? Contiguous Linked Indexed

A FAT (file allocation table) based file system is being used and the total overhead of each entry in the FAT is $4$ bytes in size. Given a $100 \times 10^6$ bytes disk on which the file system is stored and data block size is $10^3$ bytes, the maximum size of a file that can be stored on this disk in units of $10^6$ bytes is _________.

Consider a hard disk with $16$ recording surfaces $(0-15)$ having $16384$ cylinders $(0-16383)$ and each cylinder contains $64$ sectors $(0-63)$. Data storage capacity in each sector is $512$ bytes. Data are organized cylinder-wise and the addressing format is $\langle \text{cylinder no.}, \text{surface no.}, \text{sector no.} \rangle$ . A …

The data blocks of a very large file in the Unix file system are allocated using

In the index allocation scheme of blocks to a file, the maximum possible size of the file depends on