Re: [PATCH 0/1] Enable inter server to server copies on a export

[dai.ngo@oracle.com]

On 11/1/21 12:02 PM, Steve Dickson wrote:
>
>
> On 11/1/21 11:40, J. Bruce Fields wrote:
>> On Mon, Nov 01, 2021 at 11:30:48AM -0400, Steve Dickson wrote:
>>> Hey!
>>>
>>> On 10/29/21 15:14, J. Bruce Fields wrote:
>>>> On Fri, Oct 29, 2021 at 01:30:36PM -0400, Steve Dickson wrote:
>>>>> On 10/29/21 12:40, J. Bruce Fields wrote:
>>>>>> Let's just stick with that for now, and leave it off by default 
>>>>>> until
>>>>>> we're sure it's mature enough.  Let's not introduce new 
>>>>>> configuration to
>>>>>> work around problems that we haven't really analyzed yet.
>>>>> How is this going to find problems? At least with the export option
>>>>> it is documented
>>>>
>>>> That sounds fixable.  We need documentation of module parameters 
>>>> anyway.
>>> Yeah I just took I don't see any documentation of module
>>> parameters anywhere for any of the modules. But by documentation
>>> I meant having the feature in the exports(5) manpage.
>>
>> I think I'd probably create a new page for sysctls (this isn't the only
>> one needing documentation), and make sure it's listed in the "SEE ALSO"
>> section of the other man pages.
>>
>>>>> and it more if a stick you toe in the pool verses
>>>>> jumping in...
>>>>
>>>> If we want more fine-grained control, I'm not yet seeing the argument
>>>> that an export option on the destination server side is the way to do
>>>> it.
>>>>
>>>> Let's document the module parameter and go with that for now.
>>> Now that cp will use copy_file_range() when available,
>>> what are the steps needed to enable these fast copies?
>>
>> 1) Make sure client and both servers support NFSv4.2 and
>> server-to-server copy.
> Something is already figuring this out... The only time
> the client sends a COPY_NOTIFY and COPY is when both
> mounts are 4.2. I have not looked into but that is what
> the network traces are showing.
>
>>
>> 2) Make sure destination server can access (at least for read) any
>> exports on the source that you want to be able to copy from.
> How can one server know what the other server has exported
> or access to??
>
>>
>> 3) echo 1 >/sys/module/nfsd/parameters/inter_copy_offload_enable on the
>> destination server.
> Who would be doing this? Plus this would not survive over a reboot.
> An export would as well a /etc/modprobe.d/ file.

You can add a line in /etc/modprobe.d/nfsd.conf:

options nfsd inter_copy_offload_enable=Y

to enable the option.

-Dai


>
> I can see the admin setting up the export but I really
> don't see the admin doing the echo or creating the file
> esp since the neither would is documented.
>
> steved.
>