topic Re: Fast File Xfer in Operating System - OpenVMS

Fast File Xfer

Jack Trachtman — Thu, 24 May 2012 22:55:02 GMT

I have a need to do a one-time transfer of a number of binary, moderately large (up to 500GB) files from an OpenVMS system to an AIX (Unix) system. Since the VMS app must be shut down to free the files, I am looking for the fastest method of doing the file xfer so I can then restart the app.

Obviously using FTP will work, but is there any way to optimize this? Are there any other methods? (Looks like the Unix environment has utilities like rsync which can do an on-the-fly compression & decompression, but that isn't available on VMS).

TIA

Re: Fast File Xfer

Andy Bustamante — Thu, 24 May 2012 23:20:43 GMT

Without more detail some quick questions:

Do you have GB adaptors on both servers?

Do you have the disk available to make a copy of your data? Copy the files then transfer the copies.

You can zip files on the VMS side then transmit the archives, assuming space allows. Time spent in zip/unzip may or may not improve total transfer time depending on the data. Disk resource question from above applies.

Is a common tape device available? Copy the data to an tape, carry tape to your AIX system and read. "Never underestimate the bandwidth of a station wagon full of tapes . . . "

Re: Fast File Xfer

John McL — Thu, 24 May 2012 23:23:32 GMT

if it's only a matter of getting the data across and then the application restarting on VMS, then do you have space to make a local copy of the files using your own choice of weapon - COPY, BACKUP (copy), BACKUP (image) ...?

If you can create a local copy you can restart your application and then worry about how to transfer the copied files to the Unix system.

An alternative would be to

- add a new member to a shadow set,

- let the catch-up copy/merge complete

- shut down the application

- remove that new disk

- restart the app

- then worry about how you get the copy across to Unix.

Re: Fast File Xfer

Craig A Berry — Fri, 25 May 2012 00:16:29 GMT

You could try sftp -"C" which enables ssh's compression capability.

Re: Fast File Xfer

Bob Blunt — Fri, 25 May 2012 01:41:20 GMT

Shadow the database (or whatever) disk and wait for the copy to complete. Shutdown the application, dismount the 2nd/new shadow member, restart the app. Mount the disk that was the 2nd member and transfer. If they have some form of journaling turn it when restarting the app and then when you're done with the transfer move the journal and roll it in.

That seems like the fastest/simplest/safest solution to me and from my experience it isn't often that you get all three points of the triangle in one deal without a criminal consumption of money.

bob

Re: Fast File Xfer

Steven Schweda — Fri, 25 May 2012 04:38:35 GMT