While watching the output of iostat -dxz -w10 -n100 to monitor the progress/performance of a dump(8) process straight to a tape, I found out something interesting and disappointing at the same time: The disk read throughput was exactly twice as high as the tape write throughput, throughout the entire dump phases 4 and 5, i.e. dumping actual inodes. Disappointing, because the tape drive utilization (%busy) was lingering around 35%-50% for most of the time; I didn't expect the disk would be the bottleneck. :p
I want to believe that this indicates a bug in dump(8) which causes each disk block to be read twice, but being no UFS expert in any sense, I wonder: Could this behavior be by design, and would there be any room for improvement? Puzzled, Eugene _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
