dump(8) estimates, help.

[Kjell Eriksson]

How does dump(8) calculate the number of blocks it will use for a backup?
My OS is SunOS 3.2 (a BSD derivative).

After reading through dump(5) I thought the following would be close:

		2 (for the TS_TAPE + TS_END blocks)
	+ 2 * ( 1 + (nnumber of inodes / 1024))
	+ for each used and new inode 1 + the number of allocated blocks +
					one extra block per 0.5 MB

To the modified inodes you have to add the directories leading to the
modified inodes.

I dump only regular, directory, block and character special and symbolic
link inodes.

My estimate is more than 10% lower than dump(8)s so
what have I forgotten?

No, I don't have access to the dump source.
Yes I know. I could do 'dump | script >size.of.dump' but I want the values
	for all 10 levels. 
No, my dump doesn't have the '-e' flag for estimate.

Thanks in advance.

Kjell E.

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