Faster uploads to a ZFS network filler?

[Alan Somers]

On Sun, May 2, 2021 at 8:20 PM joe mcguckin <joe at via.net> wrote:

> I have a FreeBSD 12.2 system running with SAMBA. Up loading large files
> (e.g. video files) I notice the first 700-800 Mb goes pretty quickly, but
> around 800Mb, it pauses then proceeds at about half or 1/3
> normal speed.
>
> Is there a tunable parameter I can change to improve this behavoir? The
> server has plenty of memory, can I tell ZFS, SAMBA or the kernel to use
> more memory for caching?
>
> Thanks!
>
> Joe
>

By default ZFS is already very greedy with RAM.  In fact, that's probably
why you notice the speed cliff.  That first 700-800 is probably going into
RAM, and then it slows down when the server becomes limited by disk
throughput.  What does gstat show you.  Are the disks saturated?
-Alan