neil lehrer nlehrer@ibb.gov writes:
we are finally getting legato networker going with ndmp. my f760 is running 5.36r2. it has a directly attached spectralogic treefrog. the sysstat data below is running at 1 second intervals. the filer is not being used yet, we are testing. i notice a regular pattern of cpu util going from about 10 to 20 to 30 to 40% and then back down. then quiet at about 7% for about 10 seconds then up and down again. is this normal for backup? thanks.
[...]
CPU NFS CIFS HTTP Net kB/s Disk kB/s Tape kB/s Cache in out read write read write age 7% 0 0 0 0 0 5676 16 0 5407 41 7% 0 0 0 1 1 5645 0 0 6335 41 7% 0 0 0 1 0 5876 0 0 5960 41 7% 0 0 0 1 1 5456 16 0 5530 41 10% 0 1 0 1 1 6190 0 0 6150 41 22% 0 0 0 14 26 8312 0 0 8479 41 29% 0 0 0 14 26 12840 212 0 12485 41 41% 0 0 0 40 78 10868 0 0 10936 41 22% 0 0 0 14 26 9709 0 0 9533 41 28% 0 0 0 27 52 9820 16 0 9400 41 22% 0 0 0 14 25 11816 0 0 12349 41 10% 0 0 0 1 1 7207 0 0 7011 41 31% 0 0 0 27 52 9232 16 0 9400 41 12% 0 0 0 0 0 9305 0 0 9779 41 8% 0 0 0 1 0 6916 0 0 6820 41 9% 0 0 0 1 0 7471 16 0 7565 41
I tried running a "sysstat 1" during our dumps this evening (dump, not ndmp, but it shouldn't make too much difference; tape drive is a DLT7000). The filer was only moderately quiet at the time though, and the 10 second periodicity I saw was clearly due to the CPs. That shouldn't be the case for you above: in fact I don't really understand why you have a trickle of disk write activity every 3 seconds at all. Does this happen even when a dump is not running?
Anyway, your dump rate would seem to be limited by the tape drive, and the disk read rate matches it very closely. The periods with higher rates are probably due to better compression being achieved. Better compression may correspond to smaller files, which would push the CPU rate up. What sort of data have you populated the filer with for these tests?
Chris Thompson University of Cambridge Computing Service, Email: cet1@ucs.cam.ac.uk New Museums Site, Cambridge CB2 3QG, Phone: +44 1223 334715 United Kingdom.