A HITCHHIKER'S GUIDE TO ABSTRACTIONS
		   in Margo Seltzer's hash package

		      by Theodore Ts'o, 2/25/91

The Disk Layout

	The contents of a hash file consists of a hash header,
followed by an alternating sequence of bucket pages followed by
Bitmap/Overflow pages:

=============================================================================
| 	 |	  | 	     |        |          |	 |          |
|	 | 1	  | Bitmap/  | 1      | Bitmap/  | 2 	 | Bitmap/  | 4
| Header | Bucket | Overflow | Bucket | Overflow | Bucket| Overflow | Bucket
|	 | Page   | Page(s)  | Page   | Pages    | Pages | Page     | Pages
|        |        |          |        |          |	 |	    |
=============================================================================

Each block of bucket pages represents a generation