Index allocation 48 1
- 1. Indexed Allocation A modification of linked allocation where the disk block pointers for a file are all placed in an index block. 1 http://raj-os.blogspot.in/ 1
- 2. Example of Indexed Allocation http://raj-os.blogspot.in/ 2
- 3. Indexed Allocation • File allocation table contains a separate one level index for each file • The index has one entry for each portion allocated to the file • File indexes are not stored as part of file allocation table 3 http://raj-os.blogspot.in/ 3
- 4. Indexed Allocation • File indexes are stored in separate block and the entry for the file in the file allocation table points to that block • Allocation may be on basis of either fixed size block or variable size blocks 4 http://raj-os.blogspot.in/ 4
- 5. Indexed Allocation Advantages • No external fragmentation • provides efficient random access • Easily map bad disk blocks 5 http://raj-os.blogspot.in/ 5
- 6. Indexed Allocation Advantages • No external fragmentation • provides efficient random access • Easily map bad disk blocks 5 http://raj-os.blogspot.in/ 5