Metro Mirror — Main page

Use this page to set up Metro Mirror relationships between source (primary) volumes and target (secondary) volumes to allow for application data recovery, failover to remote sites for disaster recovery, and remote migration of data and offsite backups.

Introduction

This page is the starting point for creating new volume pairs for Metro Mirror relationships. You can select the storage complex (storage unit and LSS, for example) from which to create volume pairs between source (primary) and target (secondary) volumes. For new volume pairs, this operation starts the transition of two simplex volumes into a volume pair in the duplex pending or duplex state.

Note: Before you can create volume pairs, you must create paths between a source LSS in a specified storage unit and a target LSS in a specified storage unit.

This page also displays existing established volume pairs that are assigned to the storage complex (storage unit and LSS, for example) that you selected. It displays the type of relationship for which the specified volume pair is participating, and the current state of that volume pair. If your storage enterprise includes an ESS 2105 and you have configured a Copy Services domain to use ESS volumes, the source ESS and target ESS serial numbers from which those volumes are assigned are displayed. If the table is empty, no volume pairs have been defined for the selected storage complex.

You can select the volume pair that you want to manage by selecting the check box that is associated with the volume pair. The Select Actions options are changed based on the attributes of the selected volume pair, which determine the possible actions that can be performed on the volume pair. The following are actions that can be display for the selected volume pair.

Delete: The relationship between the selected volume pair is deleted.
Suspend: Application I/O to the source volume is stopped and data is not copied to the target volume of the selected volume pair during the suspension. You can select to suspend the volume pair at either the source or target volume. Data is allowed to continue when you select the Resume action.
Convert to synchronous: The selected volume pair converts to Metro Mirror mode and allows the volume pair to be synchronized.
Resume: The data is allowed to be copied to the source volume of the volume pair.
Recover failover: A failover operation turns its secondary volume into a primary volume and suspends the volumes for the selected volume pair. A failover operation is always followed by a failback operation.
Recover failback: A failback operation copies all required data from its target volume to the source volume in order to resume mirroring for the selected volume pair.
Properties: The status of the selected volume pair is displayed. For example, you can view how many tracks of data need to be copied from the source to the target volume of the selected volume pair.

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

Menu path

Real-time manager > Copy services > Metro Mirror > Go

Fields

Storage complex

The nicknames of storage complexes that are available for selection. When you create new volume pairs, the storage complex (and storage unit and LSS, for example) that you select through filtering determines where the selection of volumes are accessed. Nicknames are created by the user 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.

A storage complex describes a group of storage units such as the DS6000™s that is managed by a single management console. If you have only one DS6000 storage unit, then your storage complex consist of one storage unit.

Storage unit

The nickname of storage units that are available for selection. This list can include any nickname that is associated with any 2107, 1750, and 2105 Model 800 that is currently displayed in the Storage units main page. A storage unit consists of a single DS6000.

Resource type

The type of resource (LSS, Host, Volume group, Show All Volumes) from which to select volumes for remote mirror and copy functions. The value of the selection in this field determines the field that is displayed to the right of this field. The default value for Resource type is LSS. The following resource type values and the respective field names are displayed:

For LSS: Specify LSS
For Host: Specify Host attachment
For Volume Group: Specify Volume group
For Show All Volumes: Specify Storage type

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.

Specify Host attachment

The list of host attachment identifiers that are available for selection. A host attachment identifies the type of interface, such as Fibre Channel Arbitrated Loop (FC-AL), that is used to connect open-systems and zSeries hosts to invoke and manage remote mirror and copy functions.

Specify Volume group

The list of volume groups that are available for selection. A volume group, specified as a nickname, is a collection of logical volumes.

Show All volumes

"All FB Volumes" or "All CKD Volumes" that are available for selection. If "None selected" is selected, the table is empty.

For the zSeries^® environments, the data that is stored in a storage unit is arranged in a count-key-data (CKD) format. For the open system environments, the data that is stored in the storage unit is arranged in a fixed-block (FB) format.

Select the Metro Mirror relationship that you want to work with from the table.

Select

Check the select box to perform actions on specific table rows.

Source ESS serial

The serial number of a particular ESS from which specific source volumes that are participating in the Metro Mirror relationship are included. For example, an ESS is designated as 2105:14727, where 2105 is the device type and 14727 is the ESS serial number.

Source nickname

The nickname that identifies the source volume that is part of aMetro Mirror relationship.

If you click on a link for a particular relationship in the table, the Metro Mirror properties page is displayed. If no relationship exists, the table is empty.

Source Number

The volume number (or name, such as 1E2C) of the source volume, where the number is a four-hexadecimal value that consists of the LSS number and the volume number. For example, LLVV, where LL is the LSS number and VV is the volume number.

Target ESS serial

The serial number of a particular ESS from which specific target volumes that are in a Metro Mirror relationship are included. If you click on a link for a particular relationship in the table, the Metro Mirror properties page is displayed. If no relationship exists, the table is empty.

Target nickname

The nickname that identifies the target volume.

Target Number

The volume number (or name, such as 1E2C) that identifies the target volume, where the number is a four-hexadecimal value that consists of the LSS number and the volume number. For example, LLVV, where LL is the LSS number and VV is the volume number.

Type

The type of relationship to create:

Metro Mirror: Provides real-time mirroring of logical volumes between two storage units that can be located up to 300 km from each other. It is a synchronous copy solution where write operations are completed on both copies (local and remote site) before they are considered to be complete.
Global Copy: Provides real-time mirroring of logical volumes between storage units in a nonsynchronous manner, where the order of updates is not strictly maintained. This means that I/O write completions are returned to the application after they have been committed to the primary storage unit.

State

The state of a relationship, which can include the following states:

Full duplex: The state of a volume pair after Metro Mirror has completed the copy operation of the source volume to the target volume. At this time, the volume pair is synchronized, and all writes have been applied from the source to target volume.
Copy pending: The initial state of a defined volume pair. Metro Mirror is in the process of copying data from the source volume to the target volume. During the pending period, the volume pair is not synchronized.
Suspended: The state of the volume pair when the source storage unit cannot complete a write operation to the target storage unit or when the volume pair has been suspended manually.