Post reply

Scheduled SQLIO has invalid results

  • January 24, 2014 at 3:27 pm

    #303353

    I just ran into a weird problem.

    I had created windows scheduled task to run a batch file of various sqlio tests over a period of time, the output was then piped into a log file. Everything worked fine but the numbers from sqlio had dropped significantly than when running it directly through command line.

    Long story short, I figured out that if I schedule sqlio even though it ran, the results were significantly slower than through the command line (see example)

    Has anyone experienced this before? I'm running under my credentials (Admin), and under the highest privileges, I wasn't aware of any throttling on Task Scheduler.

    [font="System"]

    Random Reads (cmd)

    IOs/sec: 1030.93

    MBs/sec: 8.05

    Random Reads (scheduled)

    IOs/sec: 79.32

    MBs/sec: 0.61[/font]

    Thanks for your input.

  • January 24, 2014 at 7:08 pm

    #1683301

    You need to specify a suitable offline time to run the Sqlio comands,

    -----------------------------------------------------------------------------------------------------------

    "Ya can't make an omelette without breaking just a few eggs" 😉

  • January 24, 2014 at 7:33 pm

    #1683304

    Thanks for the response, but there is no activity on this machine aside from this process. The scheduled task was scheduled to run every 30 minutes for a period of 2 days, and the scheduled sqlio is consistently producing very low results compared to executed through command prompt.

    I have since disabled the job and have a batch file looping and it is producing the results I expected.

    I may add that I'm running this testing our new san so could it be related? I hadn't tried scheduling it to the DAS.

  • January 24, 2014 at 8:39 pm

    #1683307

    UPDATE: Since I hadn't tried it on the local disk I decided to try this on my laptop

    For the test I had scheduled a batch file to run the following:

    sqlio -kR -t8 -s120 -o8 -frandom -b8 -BH -LS c:\TestFile.dat >> log1.log

    then ran the following from a command window after that had finished:

    sqlio -kR -t8 -s120 -o8 -frandom -b8 -BH -LS c:\TestFile.dat >> log2.log

    Here is difference.

    manual:

    IOs/sec: 29747.27

    MBs/sec: 232.40

    scheduled:

    IOs/sec: 3348.37

    MBs/sec: 26.15

Viewing 4 posts - 1 through 3 (of 3 total)

You must be logged in to reply to this topic. Login to reply