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On 06/11/2014 11:49 AM, Stefan G. Weichinger wrote: |
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> Am 11.06.2014 12:41, schrieb thegeezer: |
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> |
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>>> everything around 380 MB/s ... only ~350 MB/s for |
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>>> /dev/vg01/winserver_disk0 (which still is nice) |
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>> |
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>> OK here is the clue. |
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>> if the LVs are also showing such fast speed, then please can you show |
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>> your command that you are trying to run that is so slow ? |
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> I originally noticed that virt-backup was slow so I looked into it and |
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> found some dd-command. |
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> |
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> My tests right now are like this: |
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> |
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> |
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> |
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> booze ~ # dd if=/dev/vg01/winserver_disk0 bs=1M of=/dev/null |
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> ^C25+0 Datensätze ein |
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> 24+0 Datensätze aus |
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> 25165824 Bytes (25 MB) kopiert, 13,8039 s, 1,8 MB/s |
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> |
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> booze ~ # dd if=/dev/vg01/winserver_disk0 bs=4M of=/dev/null |
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> ^C6+0 Datensätze ein |
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> 5+0 Datensätze aus |
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> 20971520 Bytes (21 MB) kopiert, 12,5837 s, 1,7 MB/s |
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> |
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> booze ~ # dd if=/dev/vg01/winserver_disk0 of=/dev/null |
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> ^C55009+0 Datensätze ein |
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> 55008+0 Datensätze aus |
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> 28164096 Bytes (28 MB) kopiert, 12,611 s, 2,2 MB/s |
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> |
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> So no "copy from-to same disk here" ... should be just plain reading, right? |
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> |
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> virt-backup does some ionice-stuff as well, but as you see, my |
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> test-commands don't. |
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> |
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> # cat /sys/block/sdc/queue/scheduler |
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> [noop] deadline cfq |
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> |
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> -> noop scheduler to let the controller do its own scheduling |
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> |
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> |
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> |
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> thanks, Stefan |
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> |
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> |
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> |
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just out of curiosity, what happens if you do |
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# dd if=/dev/vg01/amhold of=/dev/null bs=1M count=100 |
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# dd if=/dev/sdc of=/dev/null bs=1M count=100 |
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