[Info-vax] Mounting NFS disk with /DATA non-default parameters

[Sum1]

On 2013-01-11 19:47:30 +0000, glen herrmannsfeldt said:

> Sum1 <not at here.com> wrote:
> 
> (snip, someone wrote)
>>>> Doing a TCPIP MOUNT blah will give a default read/write size of 8192
>>>> according to TCPIP HELP MOUNT /DATA.  If I want to increase the size of
>>>> the chunks transmitted, I expect that I can issue a TCPIP MOUNT/DATA=X,
>>>> where X is some multiple of 512.  If I did /DATA=16384, I expect that I
>>>> will be transferring 16k chunks.
> 
> (then I wrote)
>>> As well as I understand it, yes, you can do that.
> 
>>> Are you using UDP or TCP?
> 
> (snip)
> 
>>> Going to jumbo packets might be more useful.
> 
> (snip)
>> Thanks for the useful reply.  The "dumb" switch won't support
>> Jumbo packets and there is no spare slot on the DS10L.
> 
> You still didn't say UDP or TCP.
> 
> I started using NFS before there was NFS/TCP.
> 
> With UDP, the size specifies the size of the UDP packet, which
> is then fragmented by IP if bigger than the MTU for the link.
> 
> For local networks, the usual way NFS is used, that works well.
> But fragment reassembly fails if any frame is lost, and that can be
> much slower than anything else. Also, Sun traditionally ran UDP without
> checksum, relying on the ethernet checksum. Again, works fine for local
> networks, not so well through the Internet.
> 
> For NFS/TCP, I would not expect much difference in transfer size.
> 
>> I am trying to improve the rate at which data arrives from the server
>> to the DS10L - there is a web server running and it receives requests
>> for photos, most of which are 300-300K.  Increasing the transfer size
>> may make a small but noticable improvement in the photo display time???.?
> 
> I think I wouldn't try changing the size until I needed to
> transfer gigabyte files, and then would also want jumbo frames.
> 
> At least the Sun NFS implementations would read ahead (on the
> physical disk) and have the data ready to go. I don't know
> if the VMS ones do that.
> 
> -- glen

Glen

My apologies - UDP, but I can use either.

This is just a home setup and to replace the switch with jumbo frames 
makes sense, I was just hoping to explore options to get data to the 
OpenVMS web server a little faster before trying infrastructure changes.

But many thanks for your help.