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AS400 V6R1 very slow transfer rate with DMX4 doing backup
Hi Gents,
We have a DMX4 (5773 code) connected to AS/400 with V6R1 Operating System. There are 2 FC ports between AS/400 and DMX4 and is dedicated to do backup from disk (BCV) to LTO4. The transfer rates are very slow, maximum 20Mb/s but normally 7or 8 Mb/s,
We have analysed the btps and appeared the information listed below:
-Disks %Util 30% as average. Maximum 70% (only peaks)
-DMX4 Ports:10%
IBM saids that the CPU is not working because has not perfomance from disks.
Our point of view is that the DMX4 is not receiving I/O from the host.
The question is:
Anyone know any cause or parameter to change in AS/400 to fix this poor perfomance?
Thanks in advance,
Jose
Quincy561
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October 25th, 2011 05:00
What is the IO size being issued from the host? This will show up in the BTPs.
Also could be the IO is not sequential. This also could explain the throughput. If it is random, adding more processes or threads to the job if possible could increase throughput.
JAG5
4 Posts
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October 25th, 2011 08:00
Hi,
Regarding the I/O size reported by the BTP, the results are listed below:
-Maximum:60 Kbytes.
-Average:10 Kbytes.
I am agree with you, the IO is not sequential, we can look it on the graphs.
Thanks a lot for you help.
Best Regards,
Jose
Quincy561
1.3K Posts
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October 25th, 2011 08:00
10k IO size is a bit small to maximize throughput.
JAG5
4 Posts
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October 26th, 2011 09:00
Thanks a lot