Re: [Nbd] [PATCH v2] doc: Add NBD_CMD_BLOCK_STATUS extension

[Alex Bligh <alex@...872...>]

On 5 Apr 2016, at 00:08, Wouter Verhelst <w@...112...> wrote:

> 
> if bit 0 in the latter field is set, that means the block is allocated
>  on the original device
> if bit 1 is set, that means the block is allocated on the first-level
>  snapshot
> if bit 2 is set, that means the block is allocated on the second-level
>  snapshot

This is what I originally thought Eric was proposing. The issue
is that in common servers the 'dirtiness' is at a different
allocation / blocksize from the allocation status. So you
really want 2 different bitmaps.

-- 
Alex Bligh