Re: COW fs (Re: Editing-in-place of a large file)

Pavel Machek
2001-09-17T22:37:43Z

Hi!

> - Keep a hash of the contents of blocks in the buffer-cache.
> - The kernel compares the hash of each block write to all blocks already
> in the buffer-cache.
> - If a duplicate is found, the kernel generates a COW link instead of
> writing the block to disk.
>
> Obviously this would involve large amounts of CPU. I think a simple

Why? If you hashed the hashes, you could do it very fast.
Pavel
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