Poor rsync performance between 11iv2 systems

[Corey Boyer]

I'm having a bit of trouble with relatively slow rsync transfers between two 11iv2 systems with rsync 2.6.8 (from the A.07 release of the IE CD.

I'm seeing an average of the following among the various protocols when transferring an approximately 2GB file between the servers:

NFS: 94MBPS
FTP: 88MBPS
RCP: 67MBPS (approximate - measured via "time")
SCP: 24MBPS
rsync via RCP (-e remsh): 23MBPS
rsync via SSH: < 20MBPS, even with blowfish

The servers both have dual gigabit NICs (AB352-60001s) and the servers themselves are connected by a bonded 2GBPS lan link, so I'm not worried about performance in that respect. I've tried adding the following flags in serveral experiments to rsync without much speed increase (I can make it up to about 30MBPS, but nowhere close to straight RCP):

-W (little difference)
No compression (remsh gives me about 7-10MBPS with -z)
Tweaking the block size with -b (little difference)

Finally, I've tried two different HP-UX systems, and performance is pretty similar.

I'd appreciate any help or advice with this, as I'm basically at a loss at this point.

Thanks much in advance!
- Corey

[Steven E. Protter]

Shalom Corey,

Things to check:
1) landamin -x lan# make sure you are getting the speed and duplex you expect.
2) You should be using the -e ssh option with rsync and therefore need to make sure the Secure Shell version is clear on both systems. If you are using this option the data stream is encrypted and this should be encrypted. Note that the scp performance is similar to the rsync performance, almost identical.

Sure NFS is faster, it doesn't encrypte the data.

3) Make sure both systems are current on performance patches, I also recommend security and the latest b-annual update QPK for 11i v2

SEP

[Corey Boyer]

Thanks for the response!

I'm at 1000/auto on both systems, so that should be OK:

bash-3.00# lanadmin -x 0
Speed = 1000 Full-Duplex.
Autonegotiation = On.

The encryption overhead doesn't surprise me - but the differential between RCP versus rsync via _remsh_ does. Particularly with -W option (basically disabling the rsync algorithm, correct?).

SSH (even with -e "ssh -c blowfish") is rather slow, but it's a bit out of date on both systems, so I'll reserve judgement on that until I can deploy the new release and any relevant performance patches to a test box. Just wondered if there was an easy way to clear up the unencrypted performance, as it will be a bit until I'm able to bring it offline to do a QPK upgrade.

Thanks again!
- Corey

[meekrob]

Hi Corey ,

please can you tell me how you eliminate the demand of password when you used rsync ,
i have this problem and till now always i'm asked for a password ,

Thank you

[Corey Boyer]

Hi -

That's generally a bad idea for rsh, unless you're in a very well controlled environment. But check out .rhosts for per-user trusts and /etc/hosts.equiv for per host.

SSH is a little trickier:

http://www.cvrti.utah.edu/~dustman/no-more-pw-ssh/

Be sure that you have all permissions set correctly - it's very picky about that.

Thanks!
- Corey