3 Replies Latest reply on Aug 13, 2015 12:30 PM by jaminsql

    Storage I/O tab automatically disabled

    dhaws

      Has anyone run into the following message?  If so, is there any way to override the limit?  If so, has anyone come up with a rule of thumb to apply on how to determine how far to push the limit, or whether or not it is advisable to even change the limit.  I'm looking for possible options to enable this tab; or...any other avenues that others may have taken to bridge this gap.

       

      Storage I/O has been automatically disabled for this database instance due to the large number of files in this database instance. This was done because gathering I/O data for a large number of files may negatively affect the performance of both DPA and the database instance.

      353 files detected. Current limit is 250.

        • Re: Storage I/O tab automatically disabled
          kathleen.gibbs

          Hi Daniel,

           

          I am sorry it took me so long to get back with you. 

           

          If you to go Options - Administration - advanced options

          click on the 'Support Options' in the upper left

          select the parameter 'IO_STATS_POLL_FILE_LIMIT' and change this value

          NEXT

          Select the 'DB Instance Options' tab

          click on the 'Support Options' in the upper left,

          you will see the parameter 'IO_STATS_POLL_ENABLED'.  You can turn on the storage IO feature from here by selecting the 'Manual_ON' option.

           

          I would recommend that if there are files you know you won't care about to go to

          Options - Monitor Setup tab - I/O Configuration button

          select the instance you are concerned with from the dropdown

          go to the 'I/O thresholds tab

          from here, expand the tree and select a file you want to hide

          select the 'hide' checkbox

           

          Kathy

          2 of 2 people found this helpful
            • Re: Storage I/O tab automatically disabled
              dhaws

              Thanks Kathy!  Since I didn't want to globally increase the value, I updated the instance parameter 'IO_STATS_POLL_ENABLED' to 'Manual_ON' per your instruction.  I am checking with my colleague to determine which files we can safely ignore so as to limit the amount of monitored files.

               

              Thanks for your thorough response.  It was worth waiting for :-)

                • Re: Storage I/O tab automatically disabled
                  jaminsql

                  Kathy gave some great steps on this one but, it still has come up in a few support cases so I am adding some info here for anyone searching this item.

                   

                  There are two settings related to this that were added in 9.1. They are IO_STATS_POLL_ENABLED and IO_STATS_POLL_FILE_LIMIT

                  The file limit is system wide setting in Options -> Administration tab -> Advanced options -> Click the Support options check box -> system options tab IO_STATS_POLL_FILE_LIMIT

                  The setting for IO_STATS_POLL_ENABLED is either system wide or set at a database instance level same as above but, if set at a database level would be on the DB Instance tab.

                   

                  The IO_STATS_POLL_ENABLED has 4 settings AUTO_ON (default) this is on but, will "Auto" shut off if the IO_STATS_POLL_FILE_LIMIT is exceeded. When that happens it changes to AUTO_OFF.

                  The other settings are MANUAL_ON (IO stats poll is enabled regardless of file count) and MANUAL_OFF (IO stats poll is disabled regardless of file count.)

                   

                  So you can either change the file limit to higher amount and leave the setting as AUTO_ON then if the file limit is crossed it will change to AUTO_OFF or you could set to MANUAL_ON and ignore the limit altogether.  You do need to restart the monitor or monitor(s) that you have changed this on after the change to remove the error and start IO stats collection. Out of the box DPA will get stats on all of these files ever 20 seconds holding them in memory for up to three minutes before writing them to a database summarized to the minute. This can be tuned also setting the IO_STATS_POLL_INTERVAL.

                   

                  We had some customers that had environments as a for instance with thousands of databases and databases set up with say 2000 files.

                   

                  The bottom line is that Storage I/O was working pretty hard with all this data and consuming a lot of memory in these examples. So we opted to turn it off at a limit and let customers tune for their needs. What those are depends on your server and I think you may have to tune the file limit and perhaps the collection interval and see what works for you.

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