Topic
IC4NOTICE: developerWorks Community will be offline May 29-30, 2015 while we upgrade to the latest version of IBM Connections. For more information, read our upgrade FAQ.
1 reply Latest Post - ‏2013-12-27T22:54:38Z by CHofmeister
vkan
vkan
2 Posts
ACCEPTED ANSWER

Pinned topic XIV Performance Issue Troubleshoot

‏2013-11-19T03:43:14Z |

Hi,

I've a XIV G3 array (11.1.1 microcode) connected to Solaris 10 host running Oracle DB. DBA is complaining of slow performance from some time and sees high IO waits and response times. We have a QoS limit on this host set-up sometime back (way before DBA started seeing issues), but not sure if that may be a contributing factor. Has anyone worked on similar issue, could you tell what to check on the XIV Statistics to understand if array is the problem. Thanks!

Updated on 2013-11-19T04:15:13Z at 2013-11-19T04:15:13Z by vkan
  • CHofmeister
    CHofmeister
    10 Posts
    ACCEPTED ANSWER

    Re: XIV Performance Issue Troubleshoot

    ‏2013-12-27T22:54:38Z  in response to vkan

    vkan,

      Sorry for the delayed response.  Performance troubleshooting can get pretty deep, depending on where the issue is at.  To determine if the sloweness is on the array side, you need to check the latency (response time).  This can be done through the XIV gui, in the statistics view.  Or for live data you can use the XIV Top utility.

      With latency the lower the better.  As for what number is acceptable, that is difficult to say, as every app/server is different.  In my environment, users start complaining of slowness after 15ms, and start getting timeouts when latency exceeds 30ms.

      However even if your XIV is showing low latency, the database could still be reporting slow disk performance.  A few situations where I have seen this: High disk fragmentation, HBA Que Depth not set correctly, Not enough HBA throughput (old 1GB HBA), SAN network issues/congestion, and of course the QoS setting you mentioned.  While it may not have been an issue before, they may have changed something on there side which caused them to exceed the QoS setting.