Operating Systems 1

Tutorial 8

1. Name one problem with storing files as linked lists of blocks.
2. Name one problem with representing the free blocks on a disk as a linked list (free chain). And nominate an alternative approach.
3. What is the overhead of a file allocation table (FAT) scheme of disk block allocation, as compared to the overhead of the simple linked list approach?
4. A particular 720K floppy uses 512byte blocks, and a FAT-based file system, with 12-bit FAT entries. How big will the FAT be in Kbytes? How many disk blocks will it occupy?
5. Describe briefly how an indexed block allocation scheme works.
6. A disk uses 2K blocks, 32-bit block pointers, and is formatted with a UNIX filesystem which makes use of double indirect blocks. To how much of a file (in bytes) may a double-indirect block refer? If each inode has room for 4 double indirect block pointers (only), what is the maximum size of a file in this system?
7. What is the essential difference between a 'hard link' and a 'soft (symbolic) link'?