Paths — Main page

Use this page to work with paths for remote mirror and copy relationships. The paths are needed to communicate between a source LSS in a storage unit and a target LSS in another storage unit and to copy data from the source to the target volumes.

Introduction

A path logically connects the source logical subsystem (LSS) in a storage unit and target LSS in another storage unit. The physical path consists of the Fibre Channel Protocol (FCP) connection between two storage units, while a logical path describes the connection of the source and target volumes.

Note: Before you can create paths, you must have configured the fibre-channel I/O ports. For paths to create successfully, verify the physical connection between the storage units. In addition, you want to ensure that the ports that are used for remote mirror and copy operations are not the same ones that are used for host I/O activity.

This page is the starting point for creating paths for remote mirror and copy relationships. It allows you to select the storage complex, storage unit, and LSS from where you want to establish new paths. Paths are created from a source LSS (on a storage unit that contains the source volumes) to a target LSS (on a remote storage unit that contains the target volumes) If you create new volumes for relationships, paths for those volumes must exist before the volumes are added. If there are no listed paths on this page, then no paths have been defined. To create a path, select Create... from Select Actions.

Note: The ESS 2105 supports an intermixed configuration of ESCON^® and FCP adapters for remote mirror and copy operations. However, the DS6000™ storage units only support FCP adapters. Therefore, if you want to create a remote mirror and copy operation between a DS6000 and an ESS 2105, you must use FCP adapters.

You can add additional paths to an LSS volume pair by creating more paths. To can select paths that you want to manage by selecting the check box that is associated with the path. The action that you select from Select Actions options determine the operation that is performed on the path. The following are actions that can be display:

Delete

The path that you select is deleted from a selected source LSS to target LSS. If you delete all paths, you lose the communication path between your remote mirror and copy volume pairs.

LSS Copy Options

You can modify the values for the following options:

Concurrent copy timeout
z/OS^® Global Mirror timeout
Critical mode
Consistency group timeout enabled
Consistency group timeout

The Paths feature is accessible only from the Real-time Manager; the Paths feature is not accessible from the Simulated Manager.

Note: You can configure I/O port properties on the Storage Units page only.

Menu path

Real-time manager > Copy services > Paths

Fields

Storage complex: The nicknames of storage complexes that are available for selection. A storage complex describes a group of storage units such as the DS6000 that is managed by a single management console.
Note: Nicknames are user-specified when resources are created and can be used as part of an overall scheme or naming convention for making resources easier to identify and manage.
Storage unit: The nickname of storage units that are available for selection. This list can include any nickname associated with any 2107, 1750, and 2105 Model 800 currently that is displayed in the Storage units main page. A storage unit consists of a single DS6000.
Specify LSS: The list of LSS identifiers that are available for selection. An LSS is a group of up to 256 logical volumes that have the same disk format, either count key data (CKD) for zSeries^® environments, or fixed block (FB) for open-system environments.
Select: Check the select box to perform actions on specific table rows.

Source LSS

The source LSS from where to create a path.

Each LSS is specified by a serial number of the storage unit it belongs to and its 2-digit LSS number within the storage unit. For example, FA123:00, where FA123 is the storage unit and 00 is the LSS number. All even numbered LSSs (X’00’, X’02’, X’04’, up to X’FE’) belong to server 0 and all odd numbered LSSs (X’01’, X’03’, X’05’, up to X’FD’) belong to server 1.

Source port

The I/O port identifier of the interface, such as the Fibre Channel Arbitrated Loop (FC-AL), and the location that provides the physical link for all paths that are defined by the source LSS. The identifier is a four-digit hexadecimal character (0-9 or uppercase A-F). The location of the port uses this format: R(1-2)-E(1-8)-C(1-6)-P(1-4), where:

R is the rack location
E is the I/O enclosure
C is the card
P is the port of the adapter
Note: R1-E3-C2-P1 is an example of this format.

Target LSS

The target LSS from which a logical path will be created to the source LSS. For each I/O port, you can separately select your target I/O port.

Each LSS is specified by a serial number of the storage unit it belongs to and its 2-digit LSS number within the storage unit For example, FA123:1A, where FA123 is the storage unit and 1A is the LSS number.

Target port

The I/O port identifier and location that provides the physical link for all paths defined by the target LSS. The identifier is a four-digit hexadecimal character (0-9 or uppercase A-F). The address uses this format: R(1-2)-E(1-8)-C(1-6)-P(1-4), where:

R is the rack location
E is the I/O enclosure
C is the card
P is the port of the adapter
Note: R1-E3-C2-P1 is an example of this format.

State

The current state of the path based on the following categories:

Configuration error: A path has failed.
Establish fibre channel: The FCP path is successfully established.
FCP down: A FCP path has failed because of a communication or hardware failure.
FCP source login exceeded: The maximum number of logins for each source FCP path has been exceeded.
FCP retry exceeded: The maximum number of times that the storage unit tried to reestablish FCP paths has been exceeded.
FCP target login exceeded: The maximum number of logins for each FCP path to the target LSS has been exceeded.
FCP target unavailable: A FCP path to the target LSS is unavailable.
None: The path has no state.
Source no resources: The path failed to establish because the maximum paths have been established from the source LSS. Resources are not available at the source site for the logical paths to be established.
Retry: The attempt to reestablish path connection.
Target mismatch: Target (remote) site system adapter ID (SAID) mismatch.
Target no resources: The path failed to establish because the maximum paths have been established from the target LSS. Resources are not available at the target (remote) site for the logical paths to be established.
Target LSS mismatch: The sequence number of the storage unit at the target site does not match the number of the target LSS.
STK: This state is reserved for use by StorageTek (STK).
Timeout: A timeout has occurred. No reason available.
Unknown: The state of the path is unknown.
Path Degraded Due to High Failure Rate: Indicates that a fibre channel path is established; however, because of a high failure rate the path is degraded.
Path Removed Due to High Failure Rate: Indicates that the fibre channel path link has been removed because the path has experienced a high failure rate.