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

[Rich Jordan]

On Friday, April 8, 2022 at 6:24:37 AM UTC-5, geze... at rlgsc.com wrote:
> On Thursday, April 7, 2022 at 7:24:03 PM UTC-4, 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
> Rich, 
> 
> As Robert noted, DECnet Phase V over IP is a viable choice. In situations where the client did not want to do that change, I have used sftp quite effectively, often in concert with ZIP/UNZIP. 
> 
> As an example, in one quick test, I was able to transfer more than a terabyte of data in a reasonable time (I do not have the precise numbers in easy reach at the moment). The context was non-tape backup. The process was: 
> - Do BACKUP/IMAGE to a scratch device 
> - use ZIP "-V" to compress the BACKUP save set. Your mileage will vary, I was able to get approximately 90% size reduction. 
> - Use sftp to copy the resulting ZIP files to the destination machine 
> - UNZIP the transferred files 
> - use BACKUP to restore the saveset on the destination machine 
> 
> The above was run in multiple BATCH jobs on both sides. 
> 
> - Bob Gezelter, http://www.rlgsc.com

Thank you all for responses.  I'm not excited about the thought of installing Phase V mainly because it has been 25+ years since I even looked at it.  I can see if it is an option.  At least that I can test here at our office.

Losing current DECnet transit is not negotiable apparently; we lost that argument but that choice is with the customer and their network vendor/support; we and the VMS boxes are a side issue that just needs to deal with the change.

As noted we already do some data moves by doing backup to local disk savesets (using the /DATA_FORMAT=COMPRESS option) then FTP'ing those sets to a PC.  Fully tested so we know we can retrieve those savesets, fix the attributes, and restore them because doing even a zero compression encapsulating ZIP takes too much time for the larger savesets (ZIP would preserve the backup saveset file attributes).   

The current VMS to VMS is done with DECnet copies of individual files, or backup of folders/trees or bulk files to remote saveset via DECnet that gets restored on the remote system.