Show TOC

I/O Operations OverviewLocate this document in the navigation structure

Use

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 Start of the navigation path Current Status Next navigation step I/O Operations Next navigation step Overview End of the navigation path.

or

Open the DBA Cockpit (transaction DBACOCKPIT) and choose Start of the navigation path Performance Next navigation step I/O Operations Next navigation step Overview End of the navigation path.

You can refresh the display. To do so, choose Start of the navigation path Edit Next navigation step Refresh End of the navigation path.

You can automate this function by choosing Start of the navigation path Edit Next navigation step Automatic Refresh On/Off End of the navigation path. 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 Start of the navigation path Goto Next navigation step I/O Details End of the navigation path to display which thread accessed the individual volumes and to obtain information about the I/O 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