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- Free space file : Keep a file of free blocks on disk (for allocation)
- Bitmap : An array of bits (with an entry for each block). The bit corresponding
to a block is set or cleared (depending on whether the block is empty or being used). The
bitmap can be held in main store for efficiency - however, any system crash may cause
inconsistencies between bitmap on disc and bitmap in main store
![figure194](img9.gif)
Figure 7: Bitmap
Omer F Rana
Sat Feb 15 19:06:41 GMT 1997