Procedure documentationI/O Operations Overview Locate this document in the navigation structure

 

In the I/O Operations menu, you will find a display of disk activities.

Procedure

Open the Database Assistant (transaction DB50) or the liveCache Assistant (transaction LC10). Choose   Current Status   I/O Operations   Overview  .

or

Open the DBA Cockpit (transaction DBACOCKPIT) and choose   Performance   I/O Operations   Overview  .

You can refresh the display. To do so, choose   Edit   Refresh  .

You can automate this function by choosing   Edit   Automatic Refresh On/Off  . The display for the function for the automatic refresh is above the header line of the table (green symbol: on, red symbol: off). In the field next to this, you can specify the time interval with which the automatic refresh should take place. The default value is 5 seconds.

Result

The system displays an overview of the activities on the disks on which the volumes are stored.

You can use the number of read and write accesses to determine how many I/O operations take place in your database. You can analyze in detail the processes that cause the I/O operations on the volumes.

  • If wait queues (Queue) are displayed for accesses to a disk area, this indicates a bottleneck in accessing this disk area.

  • Choose   Goto   I/O Details   to display which thread accessed the individual volumes and to obtain information about the I/O wait queues for the individual volumes.

    You can use this display to find out whether there are bottlenecks in the I/O system. The columns Queue Length and Maximum Queue Length provide information about whether there are currently or were previously large queues of I/O requests.

More Information

Executing Performance Analysis in CCMS

DBA Cockpit: SAP MaxDB, I/O Operations Overview