Modify EC/OPC Priority

Overview

This function sets the copy speed when using EC and OPC.

The EC/OPC speed is usually set in consideration of the host's I/O load and copy processing load. The set EC/OPC speed is applied not only for the next sessions, but also for existing sessions.

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.
Note

  • EC includes EC, REC, and RAID migration.

    If the conditions below are all satisfied, REC is operated with "EC/OPC Priority" which is specified by this function. For all other cases, REC is operated with "Multiplicity" and "Priority Level" which are specified by the [Modify REC Multiplicity] function.

    • When the connection method is "Direct"

    • When the priority level is "Automatic"

    To set the connection type, use the [Set Copy Path] function.

    To set the priority level, use the [Modify REC Multiplicity] function.

  • OPC includes OPC, QuickOPC, SnapOPC, and SnapOPC+.

  • When "Automatic Priority" is selected for the EC/OPC priority, the current priority level can be checked. Refer to the [Settings (Advanced Copy)] function for details.

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.

Settings

Select the EC/OPC priority from the following five step modes.

EC/OPC Priority

Item Description Setting values

EC/OPC Priority

Select the EC/OPC priority.

  • Automatic Priority

    This mode changes the EC/OPC priority automatically in response to the operating load status.

  • High Priority

    This mode operates by making maximum use of internal resources.

    This mode greatly affects host access performance, thus should not be used during normal operation. Use when the operation load is low.

  • Middle Priority

    This mode operates slightly slower than the High Priority mode.

    Select this mode when performance is greatly affected by the High Priority mode, but the copy speed is too slow with the Low Priority mode.

  • Low Priority

    This mode reduces the effect on host access.

    Select this mode when using EC and/or OPC during operation.

  • Very Low Priority

    This mode operates slower than the Low Priority mode.

    Select this mode when performance is affected (such as when the performance of host response is reduced) by the Automatic Priority or Low Priority mode.

Automatic Priority

High Priority

Middle Priority

Low Priority

Very Low Priority

Advanced Setting

In this screen, specify the copy schedule mode.

Item Description Setting values

Copy Schedule Mode

Select the schedule mode for EC, OPC, and QuickOPC. It is not necessary to change the default value (Session Balancing) for normal use.

Setting the schedule mode for SnapOPC and SnapOPC+ is not required.

Use the [Modify REC Multiplicity] function to specify the REC schedule mode.

  • Session Balancing

    Copy sessions are scheduled evenly to each Controlling CM for a copy source RAID group (a RAID group to which the copy source volume belongs).

  • Destination RAID Group Balancing

    Only one copy session can be performed for each copy destination RAID group. This method prevents unequal loading on a specific RAID group. This may improve the copy performance when a copy destination RAID group is configured by Nearline disks or when "High Priority" is set for EC/OPC.

Caution
  • Copy performance is not improved by selecting "Destination RAID Group Balancing" in the following conditions:

    • When the type of the copy destination volume is not "Standard"

    • When the copy destination volume "Standard" and concatenated

Session Balancing (Default)

Destination RAID Group Balancing

Operating Procedures

Set the EC/OPC priority.

  1. Click [Modify EC/OPC Priority] in [Action].

  2. Specify the parameters, and click the [Set] button.

    → A confirmation screen appears.

    Note

    • Click [Advanced Setting] to specify the copy schedule mode.

  3. Click the [OK] button.

    → The selected EC/OPC priority is set.

  4. Click the [Done] button to return to the [Settings] screen.