Measure Round Trip Time

Overview

This function measures the round trip time between the local and the remote storage systems.

"Round trip time" is the time taken to make a communication between two storage systems.

Only one remote storage system can be measured at a time.

Caution

  • Registering the Advanced Copy function license or the Storage Cluster function license (*1) is required to use this function.

    *1  :  The Storage Cluster function license must be registered using ETERNUS SF Storage Cruiser.

  • Round trip time can be measured only when the connection type is "Remote". Round trip time cannot be measured when the connection type is "Direct".

  • Round trip times must be set for copy source and copy destination storage systems. Measure the round trip time after applying the copy path information to both the copy source and copy destination storage systems, and then set the results (measured value).

  • Round trip times must be measured from a static state without sending data through the line. For example, if REC sessions exist between storage systems, set the REC session status to "Suspend" before measuring.

  • Make sure that the physical line is correctly configured between storage systems before measuring. When a line has an error, the round trip time cannot be measured correctly.

  • If the path between storage systems is changed, measure the round trip time again.

  • It takes a maximum of 160 seconds to measure the round trip time.

User Privileges

Availability of Executions in the Default Role

Default role Availability of executions
Monitor  
Admin
StorageAdmin
AccountAdmin  
SecurityAdmin  
Maintainer

Refer to User Roles and Policies for details on the policies and roles.

Display Contents

The information of the remote storage systems that are currently connected is displayed.

Remote Storage System Information

Item Description

Box ID

The Box ID for the remote storage system is displayed.

Round Trip Time

The round trip time of the remote storage system is displayed.

  • If the round trip time has already been measured, the current round trip time is displayed.

  • If the round trip time has never been measured before, "Not measured" is displayed.

Connection Type

The connection type between the local and the remote storage systems is displayed.

Remote

Settings

The round trip time measurement result is displayed.

Item Description Setting values

Box ID

The Box ID for the remote storage system is displayed.

Round Trip Time

The round trip time (1 to 65535) measurement result between the local and the remote storage systems is displayed.

If a measurement error has occurred, the field is blank. The value can be changed.

The following describes the recommended round trip time.

   Asynchronous copy: within 100 msec.

   Synchronous copy: within 50 msec.

Numeric characters between 1 - 65535

(decimal)

Unit: msec.

Connection Type

The connection type between the local and the remote storage systems is displayed.

Remote

Operating Procedures

  1. Select the remote storage system that is connected by remote connection to measure the round trip time, and click [Get Round Trip Time] in [Action].

  2. Click the [Measure] button.

    → Measurement of the round trip time starts.

  3. Change the "Round Trip Time (msec)" value if necessary, and click the [Modify] button.

    → A confirmation screen appears.

    Caution

    • If the round trip time has not been entered, the [Modify] button cannot be clicked.

    • If the entered round trip time does not satisfy the input conditions, an error screen appears.

  4. Click the [OK] button.

    → The round trip time measurement result is updated in the storage system.

  5. Click the [Done] button to return to the [Copy Path] screen.