Re: [Libguestfs] nbdcpy: from scratch nbdcopy using io_uring
On Sat, Jul 31, 2021 at 06:12:16PM +0530, Abhay Raj Singh wrote:
I was able to resolve the issue caused by multiplexing where
HEADER1+DATA1...
was read as
HEADER1+HEADER2+HEADER3...
So nbdcpy is functional! and copies completely.
Though I have been trying to resolve another issue
The command below works fine (16MB)
nbdkit -v -o data ' ( 0x41 0x42 )*16777216 ' --run 'bin/nbdcpy $port
$port'
But when I use random
`nbdkit -v -o random size=16M --run 'bin/nbdcpy $port $port'`
I get
error: data written does not match expected
This is a problem :-(
It comes from here and indicates that the data you're writing doesn't
exactly match what was originally read:
https://gitlab.com/nbdkit/nbdkit/-/blob/de8dcd3a34a38b088a0f9a6f8ca754702...
I would suggest starting with a very small disk and printing out
everything that you read and write. Should help to track down the
problem.
So, I assume my code is affected by data somehow which I am not able
to find.
As it's functional now I will update the documentation to make it more
understandable and true to code and then ask for reviews from io_uring
people. I will also resume work on documenting how libnbd works and on
how to integrate io_uring with libnbd or nbdcopy.
Thanks,
Rich.
--
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