[Info-vax] VMS to VMS data copy options/performance when losing a DECnet link

Jeffrey H. Coffield jeffrey at digitalsynergyinc.com
Thu Apr 14 14:52:50 EDT 2022



On 04/14/2022 11:31 AM, Rich Jordan wrote:
> On Thursday, April 7, 2022 at 6:24:03 PM UTC-5, Rich Jordan wrote:
>> Customer has decided to turn off "legacy" DECnet support on their network. They currently use DECnet for copies between two nonclustered integrity servers that are on different IP subnets/VLANs and have Cisco doing whatever magic it does to make DECnet appear local. THis is Phase IV, not DECnet over IP.
>>
>> Is there any documentation on relative performance for bulk data transfer with preliminary data archiving (ie ZIP or backup to a local archive file so not transferring lots of individual files) on VMS using FTP/SFTP versus using NFS as the transfer mechanism? I know details matter and I don't have them yet but is one likely to be enough different that it is worth pursuing a test? Which won't be trivial given equipment availability...
>>
>> Thanks for any info
>
>
> Well, tried various combinations of the TCP protocol settings (like NODELAY_ACK), the FTP logicals for initial and append allocations, the FTP window size, etc.  FTP is doing 1.4 to 1.64Mbps (that last due to /NODELAY_ACK) and won't go any higher.   SFTP is supposed to be slower but we'll try it anyway.  For now going to locate iPerf ports for VMS and run some tests with it to see what actual throughput we are getting between the sites.
>

We had to move large save sets over FTP when a system was replaced with 
another system at a different location and we used the following setting 
to speed up the transfers:

$       TCPIP
sysconfig -r socket sb_max=2000000
sysconfig -r socket somaxconn=10240
sysconfig -r socket sominconn=10240
sysconfig -r inet tcp_sendspace=300000 tcp_recvspace=300000
sysconfig -q socket
sysconfig -q inet tcp_sendspace tcp_recvspace

I know I didn't figure this out but I don't remember where I found these 
settings.

Jeff
www.digitalsynergyinc.com



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