Re: speeding up zfs send | recv (update)

On 22/02/2023 23:17, George Michaelson wrote:
> I use mbuffer for this purpose. I'm only on protected "inside" links
> even if cross-router (ie not just a switching fabric) which may make
> my use-case a poor fit for your need.
> 
> mbuffer has several strategies around how much buffer to use, what
> rate limits to apply, I believe can do tweaks to use scatter-gather
> models (the necessary ioctls to turn things on &c but these are almost
> certainly tuned to linux)
> 
> you also need to look at your ethernet card offload. Normally
> beneficial. it can interact badly with in-kernel models of end-to-end
> flow, because it's performing its own work "on your behalf"

I tried disabling rxcsum, txcum, tso4 but then it became 10 MiB/s slower.

> I sort of miss having a "null" cipher in SSH. I didn't entirely
> understand why it got stripped out: the 'who are you" initialisation
> authorisation is beneficial, even if the datastream is (deliberately)
> unprotected. the RC2 fallback didn't seem to impose much cost, but
> thats gone too now.

It would be really useful for my usecase too.

Kind regards
Miroslav Lachman