[Samba] Can't copy large files to Windows with SMB2/3 on 10G network

[MI]

>> - smbclient [no -m option] is OK and slow (uses default SMB1/NT1?)
>> - mount.cifs -o vers=1.0 is OK and slow
>> - smbclient -m SMB2 (or -m SMB3) fails
> The above is the interesting case, as this is much
> easier to debug (in user space) than the kernel
> client.
>
> Can you give more details on *exactly* HOW smbclient -mSMB3
> fails ?

This is really strange: today I was not able to reproduce the problem. 
Neither with smbclient, nor with mount.cifs.

Tried with 2 of the 3 Windows machines which showed the original 
problem, but today all copies with file sizes from 50 GB up to 150 GB 
went fine, using SMB 3.11.

Well, it looks like we might never know what the problem was.

Thanks anyway,

MI