> > > Monitoring disk access using gkrellm, I noticed that a command like > > > > > > cat /dev/hda > /dev/null > > > > > > shows eradic disk reads ranging from 0 to 80MB/s on an otherwise idle > > > system. > > > > > > 1. Is this a hardware or software problem? > > > > Difficult to tell without more info. Can be a broken IDE disk or defective > > ribbon. > > Tried the same with 2.4.31 which shows steady behaviour with occasional dips > and pops in the msec range. > > > > 2. Is there a lightweight perf-mon tool (cmd-line) that would log this > > > behaviour graphically? > > > > You can do " readspeed </dev/hda | tr '\r' '\n' > log " with the readspeed > > tool from there : > > http://w.ods.org/tools/readspeed Try attached one. # dd if=/dev/hda of=/dev/null bs=16M On another console: # nmeter t6 b d1 ... 13:42:28.352037 bio 0 0 13:42:28.354675 bio 0 0 13:42:28.357703 bio 0 0 13:42:28.360671 bio 0 0 13:42:28.364712 bio 0 0 13:42:28.367671 bio 128k 0 13:42:28.370673 bio 0 0 13:42:28.373656 bio 0 0 13:42:28.376653 bio 0 0 13:42:28.379680 bio 128k 0 13:42:28.382656 bio 0 0 13:42:28.385819 bio 0 0 13:42:28.388651 bio 0 0 13:42:28.391736 bio 128k 0 13:42:28.394673 bio 0 0 13:42:28.397656 bio 0 0 ... -- vda
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