V8.3-1H1 Installed with Gigabit nics and slow net performance

[Robert Gezelter]

Stuart,

With all due respect, I must somewhat differ with Jim.

BACKUP is fatter, particularly if it is doing significant non-transfer scan processing (e.g., /INCREMENTAL, wildcard selections that are sparse).

For actual transfers, BACKUP and COPY should be comparable over DECnet. They both use RMS remote file access.

However, there is a difference. COPY has a good idea of how big the output file will be in advance. BACKUP does not. If you destination volume has a small extend size, this can be particularly painful. Five blocks (2,560 bytes at 1Gb/sec) means very frequent file extensions, which are expensive in a number of ways.

Modifying the LOGIN.COM of the target account with SET RMS/BUFFER_COUNT=nn/BLOCK_COUNT=nn/EXTEND_QUANTITY=nn dependent on IF F$MODE() .EQS. "NETWORK" has quite a measurable impact in many cases.

While I have not done timing tests recently, I would be unsurprised if SFTP and FTP benefited as well.

- Bob Gezelter, http://www.rlgsc.com

[MarkOfAus]

Robert,

"While I have not done timing tests recently, I would be unsurprised if SFTP and FTP benefited as well. "

I can testify to that. We used set rms/et al as you detailed to vastly increase the transfer speeds of a 500MB file transferred from Windows to VMS.

Regards
Mark