disk diagnostics

Oliver Fromme check+j327k900rs5gl138 at fromme.com
Thu Jul 27 04:39:31 PDT 2006


Bill Hacker wrote:
 > Pieter Dumon wrote:
 > > > time rm -rf world_i386
 > > 
 > > 0.070u 0.476s 20:11.87 0.0%     313+264k 7+54102io 0pf+0w
 > 
 > "The time utility executes and times the specified utility.  After the
 > utility finishes, time writes to the standard error stream, (in seconds):
 > the total time elapsed, the time used to execute the utility process and
 > the time consumed by system overhead."
 > 
 > (not necessarily in that order?)

Usually the "time" command is a shell-builtin, so the
output format may differ, depending on what shell you
use.  Use /usr/bin/time for the "real" time(1) command.

$ /usr/bin/time sleep 1
        1.00 real         0.00 user         0.00 sys
$ zsh -c 'time sleep 1'
sleep 1  0.00s user 0.00s system 0% cpu 1.002 total
$ tcsh -c 'time sleep 1'
0.000u 0.000s 0:00.00 0.0%      0+0k 0+0io 0pf+0w
$ ksh -c 'time sleep 1'
    1.00s real     0.00s user     0.00s system
$ bash -c 'time sleep 1'
real    0m1.003s
user    0m0.001s
sys     0m0.001s

 > Am I wrong in interpreting that said act took 7 1/100's of a second of CPU time 
 > for itself, needed just under half a second of system overhead, but needed 20+ 
 > minutes end-to-end to complete by the wall-clock?

Seems to be correct.  It just sat there 99% of the time
(in "biowr" state, according to top) and did nothing.

Could this be an interrupt problem?  I'd be interested
to see the output from "vmstat -i" before and after such
an rm or tar command or similar.  Also, some lines from
"iostat 5" during the rm/tar might be useful.

Best regards
   Oliver

-- 
Oliver Fromme,  secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing
Dienstleistungen mit Schwerpunkt FreeBSD: http://www.secnetix.de/bsd

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