HP-UX Support for HPN-SSH

[Hank Classe]

We are experiencing performance issues that are exclusive to our hp-ux machines connected at Gig/E speeds with scp & sftp. All the usual checks have been rendered, inclusive of temporarily flipping on ftp & finding transfer rates to be nominal. I ran across a document, 'High Speed Bulk Data Transfer on the Grid Using the SSH Protocol. Not surprising is the author's uncovering TCP window sizing & flow control issues specific to scp. On the last page the author states that HP has adopted HPN-SSH as of Spring 2007 in HP-UX. Has anyone implemented this and if so, what were your results. It would also be helpful if you could share the method of implementing it. Thanks much. Article found at www.psc.edu/networking/projects/hpn-ssh/

[rick jones]

I asked internally and was told that the HPN patches were indeed applied, but were left disabled by default as some folks who tried it actually found performance degregadation. Sounds like the reasons used to be very cautions with old FTP/FTPD default socket buffer sizes I guess. Anyway the latest HP supplied ssh can be found at:

http://h20293.www2.hp.com/portal/swdepot/displayProductInfo.do?productNumber=T1471AA


and to enable the HPN stuff one needs to edit the ssh_config on the client and the sshd_config on the server and restart the server. I was told that one could grep for "hpn" (or perhaps "HPN") in those files to find the things to tweak.

[Hank Classe]

Thanks. We'll have a look at it.