Topic
1 reply Latest Post - ‏2009-12-10T15:55:25Z by ed_pollard
infochcbflo
infochcbflo
1 Post
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Pinned topic Disk read / write is strange

‏2009-12-09T15:00:34Z |
Hello,
I have a mistake on my IBM server Linux RHE 4.
I check my disk whith this command :
while true; do time dd if=/dev/zero of=/home/star/storage_space/Local/local_5/FUSIBLE bs=1M count=10; sleep 1; done

And the result is :
##########
0+10 enregistrements lus.
0+10 enregistrements écrits.

real 0m24.005s
user 0m0.000s
sys 0m0.000s
##########
0+10 enregistrements lus.
0+10 enregistrements écrits.

real 0m0.001s
user 0m0.000s
sys 0m0.001s
##########
0+10 enregistrements lus.
0+10 enregistrements écrits.

real 0m0.001s
user 0m0.000s
sys 0m0.001s
##########
0+9 enregistrements lus.
0+9 enregistrements écrits.

real 0m0.535s
user 0m0.000s
sys 0m0.001s

I do not know why sometime the response time is very long and if it's fast.
I attach a nmon files if you want.
Thank's

Sorry for my poor english
Updated on 2009-12-10T15:55:25Z at 2009-12-10T15:55:25Z by ed_pollard
  • ed_pollard
    ed_pollard
    16 Posts
    ACCEPTED ANSWER

    Re: Disk read / write is strange

    ‏2009-12-10T15:55:25Z  in response to infochcbflo
    We will need to know a little more about your environment before even attempting to answer the question.

    What is the exact version of RHEL4? (the ourput of uname -a and `cat /etc/issue` would be helpful)
    What type of system?
    What kind of storage are you using?

    Is there anything else running on the system that could be I/O intensive at the time you perform these tests?

    -Ed