Messages in this thread | | | Date | Sat, 17 Sep 2005 07:50:10 +0200 | From | Willy Tarreau <> | Subject | Re: Eradic disk access during reads |
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On Sat, Sep 17, 2005 at 07:26:11AM +0300, Al Boldi wrote: > 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.
> 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
Then you just have to graph $6 (kB/s) versus $1 (bytes read). There may be other tools which do all this automatically though.
Regards, Willy
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