samba - Aug 2023 - Increase data length for SMB2 write and read requests for Windows 10 clients

On 8/21/23 11:53, Jones Syue ??? via samba wrote:
>> OH - that's *really* interesting ! I wonder how it is
>> changing the SMB3+ redirector to do this ?
> 
> It looks like applications could do something and give a hint to SMB3+
> redirector, so far not quite sure how to make it,
> per process monitor (procmon) could show that write I/O size seems
> could be pass from the application layers,
well, sure, the application layer drives IO with the IO size it chooses. 
But when the application layer issues IOs larger then the maximum IO 
size allowed by SMB (8 MB iirc), the Windows SMB kernel client will 
segment the larger application segments into smaller ones.

-slow


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On Mon, Aug 21, 2023 at 03:19:59PM +0200, Ralph Boehme
wrote:
>On 8/21/23 11:53, Jones Syue ??? via samba wrote:
>>>OH - that's *really* interesting ! I wonder how it is
>>>changing the SMB3+ redirector to do this ?
>>
>>It looks like applications could do something and give a hint to SMB3+
>>redirector, so far not quite sure how to make it,
>>per process monitor (procmon) could show that write I/O size seems
>>could be pass from the application layers,
>
>well, sure, the application layer drives IO with the IO size it 
>chooses. But when the application layer issues IOs larger then the 
>maximum IO size allowed by SMB (8 MB iirc), the Windows SMB kernel 
>client will segment the larger application segments into smaller ones.
Fastcopy is doing *something* weird :-).

1. FastCopy (FastCopy.exe), 8MB (need to revise FastCopy default setup)
Process Name    Operation       Path    Detail
System  TCP Send        10.19.7.63:64845 -> 10.19.250.98:445    Length:
8388724, startime: 3459115, endtime: 3459149, seqnum: 0, connid: 0
System  TCP Receive     10.19.7.63:64845 -> 10.19.250.98:445    Length: 84,
seqnum: 0, connid: 0
FastCopy.exe    WriteFile       \\10.19.250.98\Public\1GB.img   Offset:
92,274,688, Length: 8,388,608, Priority: Normal

I wonder if it has it's own SMB client code
built in ?

Either that or it knows what parameters to change
in the SMB redirector to request 8MB IO.

I wonder if setting a CreateOptions allows this
somehow ?