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On Saturday 29 November 2008 11:19:47 Daniel Iliev wrote: |
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> Now let's put the assumptions aside and do a test. |
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> |
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> root@localhost # test $ cat /usr/portage/packages/All/* > test1 |
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> root@localhost # test $ cp test1 test2 |
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> root@localhost # test $ ls -lah |
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> total 2.3G |
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> drwxr-xr-x 2 root users 4.0K 2008-11-29 01:38 . |
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> drwxr-xr-x 44 root users 4.0K 2008-11-29 01:36 .. |
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> -rw-r--r-- 1 root users 1.2G 2008-11-29 01:38 test1 |
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> -rw-r--r-- 1 root users 1.2G 2008-11-29 01:40 test2 |
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> localhost test # filefrag * |
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> test1: 1125 extents found, perfection would be 10 extents |
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> test2: 1923 extents found, perfection would be 10 extents |
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> localhost test # time cat test1 > /dev/null |
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> |
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> real 0m26.747s |
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> user 0m2.110s |
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> sys 0m1.450s |
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> localhost test # time cat test2 > /dev/null |
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> |
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> real 0m29.825s |
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> user 0m1.780s |
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> sys 0m1.690s |
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|
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This is not a test unfortunately. You did one run on one file and one run on |
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another file. We do not know what else the machine was doing at that time, |
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and that unknown is a considerable one. |
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|
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Repeat your test eliminating this factor. Preferably, remount the filesystems |
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after each run and repeat 1000 times. Then analyze the statistical |
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distribution of your results. This should eliminate most random factors and |
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give a more realistic real-world view. |
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|
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-- |
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alan dot mckinnon at gmail dot com |
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