Sorry to take so long to get back to you Tobias and I hope this is still relevant. As described elsewhere in this list, I had temporarily to downgrade ssh to achieve interoperability between the OmniOS (bloody) host and the Gentoo Linux guests.
First, ssh imposes some overhead: mounty@pantry ~ $ time ssh people exit real 0m0.724s user 0m0.032s sys 0m0.012s that real figure averages around the 0.750s mark. So I decided to perform much bigger transfers to minimise its effect: mounty@pantry ~ $ dd if=/dev/zero bs=1M count=2000 | ssh people dd of=/dev/null 2000+0 records in 2000+0 records out 2097152000 bytes (2.1 GB) copied, 138.436 s, 15.1 MB/s 4096000+0 records in 4096000+0 records out 2097152000 bytes transferred in 137.657582 secs (15234555 bytes/sec) mounty@pantry ~ $ ssh people dd if=/dev/zero bs=1M count=2000 | dd of=/dev/null 2000+0 records in 2000+0 records out 2097152000 bytes transferred in 51.692313 secs (40569901 bytes/sec) 4096000+0 records in 4096000+0 records out 2097152000 bytes (2.1 GB) copied, 52.4503 s, 40.0 MB/s It is puzzling that the in and out figures are so different but I did perform each test three times and the results were approximately the same each time. On the read-off-disk test, here are all three runs: pantry ~ # dd if=/dev/vda of=/dev/zero bs=1M count=1000 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 65.3406 s, 16.0 MB/s pantry ~ # dd if=/dev/vda of=/dev/zero bs=1M count=1000 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 1.19789 s, 875 MB/s pantry ~ # dd if=/dev/vda of=/dev/zero bs=1M count=1000 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 1.85877 s, 564 MB/s which I've quoted to show that the disk must be cached. So I tried again with more data to eliminate that effect: pantry ~ # dd if=/dev/vda of=/dev/zero bs=1M count=10240 10240+0 records in 10240+0 records out 10737418240 bytes (11 GB) copied, 710.215 s, 15.1 MB/s I hope that's helpful. Michael. _______________________________________________ OmniOS-discuss mailing list OmniOS-discuss@lists.omniti.com http://lists.omniti.com/mailman/listinfo/omnios-discuss