[Libguestfs] [PATCH v2] v2v/v2v.ml: Use larger request size for -o rhv-upload

[Richard W.M. Jones]

On Mon, Feb 14, 2022 at 04:08:21PM +0000, Richard W.M. Jones wrote:
> There is a limit on the number of parallel requests in flight
> (nbdcopy --requests, default 64).  This limits the implicit buffer to
> max_requests * request_size.  That's 16MB in the default
> configuration.  Quite small actually ...
> 
> https://gitlab.com/nbdkit/libnbd/-/blob/6725fa0e129f9a60d7b89707ef8604e0aeeeaf43/copy/multi-thread-copying.c#L239
> 
> I've managed to reproduce the problem locally now so I can try playing
> with this limit.

Or rather, I thought I'd reproduced it, but after repeating the
test a few times it's just ordinary variability.

Anyhow I tried increasing the nbdcopy --requests parameter to 64->256
but it didn't change the speed (faster or slower).

Rich.

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