I/O Statistics Help


Statistics Overview

ServerNet SAN I/O consists of read and write transactions (operations) initiated by each ServerNet PCI Adapter (SPA) in the cluster. Each read or write operation by a given SPA typically results in the transfer of some number of bytes of data (read) from or (written) to a destination SPA. With the I/O Statistics view, you can select a SPA in the cluster, then view the read/write operation counts and the read/write byte counts: The ServerNet SAN operation and byte count statistics for a given SPA are cleared to zero when the associated node is booted or when the ServerNet SAN path being used by the SPA is switched (between the X and Y ports). Therefore, the non-zero operation and byte counts appear in the column (X Count or Y Count) of the active path and reflect the magnitude of the traffic since the last path switch or node boot.

NOTE: The operation and byte count numbers are approximate.


Viewing Statistics

The I/O statistics appear in two panes: Associated with each of these two panes is a SPA choice box used to select the SPA for which the I/O statistics are retrieved. The amount of vertical space allotted to each pane within the NonStop Cluster Management Suite (NCMS) window can be adjusted by dragging the horizontal line between the panes up or down or by clicking the arrowheads on the line.
 

Procedure

For either pane, view the I/O statistics as follows:
  1. Select the SPA that you want I/O statistics for with the SPA choice box next to the chosen pane.
  2. In the chosen pane, click the plus (+) sign to the left of the desired SPA pair to see the associated I/O statistics. For example, if SPA 2 was selected in Step 1, the [2, 1] SPA pair can be expanded to see the operation and byte counts initiated by SPA 2 to SPA 1.
  3. Expand all SPA pairs (click on + signs) as needed.
With the I/O statistics for a SPA pair displayed, they can be collapsed and hidden by clicking on the negative (-) sign to the left of the pair.