Hitachi Command Suite 8 User Guide

							Note: When allocating volumes from the default virtual storage machine,
you do not need to select a virtual storage machine. The default virtual
storage machine is selected by default.
7. Select the volume type and volume location.
8. Click  Advanced Options  to specify tier, drive type, drive speed, RAID
level, or parity group in the volume criteria. The storage system will
search for volumes that match the criteria.
9. Click  LUN Path Options  to configure the number of LUN paths to
allocate per host and assign or change LUN paths.
10. (Optional) Click  Host Group and LUN Settings  to configure the host
group settings and LUN number.
11. Click Show Plan  and confirm that the information in the plan summary
is correct. If changes are required, click  Back.
12. (Optional) Update the task name and provide a description.
13. (Optional) Expand  Schedule to specify the task schedule.
You can schedule the task to run immediately or later. The default setting
is  Now . If the task is scheduled to run immediately, you can select  View
task status  to monitor the task after it is submitted.
14. Click Submit.
If the task is scheduled to run immediately, the process begins.
15. (Optional) Check the progress and result of the task on the  Tasks &
Alerts  tab. Click the task name to view details of the task.
16. On the  Resources  tab, select hosts to verify that volumes have been
allocated. The virtual information is set to the allocated volumes. When a
default virtual storage machine volume is allocated, the volume is
registered to the virtual storage machine to which the host groups belong.
Tip:  When you are canceling volume allocation, you can delete the
virtual information and move the volume to the default virtual storage
machine.
Related references
•
Prerequisites for allocating volumes  on page 192
Editing virtual storage machines You can add resources or remove resources from a virtual storage machine.You can also change the name of the virtual storage machine.
To support global-active device pairs, edit the virtual storage machine to addsecondary storage system resources to a default or user-defined virtual
storage machine on the primary storage system to provide a single view of
the primary and secondary storage system resources.
Managing virtual storage machines271Hitachi Command Suite User Guide 
						

							Prerequisites
From the host, unallocate volumes that are related to resources that belong to the virtual storage machine you are removing.
Procedure 1. On the  Administration  tab, select Virtual Storage Machine , select a
virtual storage machine in the list, and then click  Edit Virtual Storage
Machine .Note: If you are performing a global-active device setup, click  Edit
Virtual Storage Machine  on the Set Up Global-Active Device
window.
2. Verify the  Name and Virtual Model and Serial No.  of the virtual
storage machine that you are modifying. If you are setting up a global-
active device pair, verify that the virtual storage machine is on the primary storage system.
3. Add or remove resources, such as parity groups or LDEV IDs, on the
virtual storage machine. If you are setting up a global-active device pair,
click  Add Storage Systems , select the secondary storage system, and
then click  OK. Then add secondary storage system resources, such as
Parity Groups , LDEV IDs , Storage Ports , and Host Group Numbers
to the virtual storage machine.
Note:  If you are performing a global-active device setup, the primary
storage system resources already belong to the default virtual storage machine.
4. When you are finished adding resources, enter an optional task
description, select whether you want to view the progress of the task, and then click  Submit.
5. (Optional) Check the progress and result of the task on the  Tasks &
Alerts  tab. Click the task name to view details of the task.
Result
The selected virtual storage machine is edited and can be verified in the list
of virtual storage machines. If you are creating a global-active device pair,
you have a single view of the primary and secondary storage system
resources.
Related concepts
•
About virtual storage machines  on page 264
Related references
•
Prerequisites for allocating resources to virtual storage machines  on page
268
272Managing virtual storage machinesHitachi Command Suite User Guide 
						

							Deleting virtual storage machinesYou can delete virtual storage machines that are no longer required. Deletinga virtual storage machine also deletes all of the virtual information about the
resources that belong to that virtual storage machine and removes the
resources from the virtual storage machine.
Prerequisites
From the host, unallocate the volumes that belong to the virtual storage
machine that you are deleting.
Procedure 1. On the  Administration  tab, select Virtual Storage Machine .
2. From the list of virtual storage machines, select the virtual storage
machine that you want to delete and click  Delete Virtual Storage
Machine .
3. Click  Submit .
4. On the  Tasks & Alerts  tab, confirm the task completion.
Result
The selected virtual storage machine is deleted.
Related concepts
•
About virtual storage machines  on page 264
Managing virtual storage machines273Hitachi Command Suite User Guide 
						

							274Managing virtual storage machinesHitachi Command Suite User Guide 
						

							7
Replicating volumes for continuousaccess
Volume replication is used for creating in-system or remote storage system
volume copies for data protection. Global-active device provides copy pair replication for active-active high availability in a multi-site environment.
□
About global-active device
□
Setting up a global-active device environment
□
Monitoring and managing global-active device pairs
□
Recovering from global-active device failures
□
Discontinuing a global-active device environment
□
Volume replication
Replicating volumes for continuous access275Hitachi Command Suite User Guide 
						

							About global-active deviceGlobal-active device employs volume replication (P-VOL and S-VOL in a bi-
directional copy pair) to provide a high availability (HA) environment for
hosts across storage systems and sites. The purpose of global-active device
is to provide data protection and minimize data access disruptions for host applications due to storage system or site failures.
A virtual storage machine represents storage resources such as parity groupsand LDEVs (volumes). To support global-active device read/write operations,
resources of the primary storage system (Serial #1) and secondary storage
system (Serial #2) are defined in the virtual storage machine to provide a
single view of the primary and secondary storage system resources.
As shown in the following figure, volumes on the secondary storage system
are assigned a virtual LDEV ID that matches the physical LDEV ID of volumes
belonging to the default virtual storage machine on the primary storage
system. The host can then access the primary or secondary volume by using
the same LDEV ID (01). This occurs when you create a global-active device
pair during volume allocation.
In addition to the example above, if the Virtual Storage Platform G1000 microcode version in both the primary and secondary storage systems is 80-02-01-XX/XX  or later, you can also create a global-active device pair by
setting, as the P-VOL, a volume that already has a virtual LDEV ID assigned
and whose resources are managed by user-defined virtual storage machines,
such as a volume migrated by nondisruptive migration. If you register a P-
VOL for a user-defined virtual storage machine, the virtual LDEV ID of
volumes on the primary storage system are used.
276Replicating volumes for continuous accessHitachi Command Suite User Guide 
						

							The global-active device environment resolves the details of all read/write
activity to the global-active device pair. For example, when the host writes
data to LDEV ID 01, data is replicated to LDEV ID 02. If the host path to
primary storage fails, the host can continue to perform read/write operations using the secondary storage volume.
When a global-active device pair is established, application server high-
availability benefits include:
• Continuous I/O: If a primary volume becomes unavailable, the host will continue totransparently access the secondary volume.
• Clustered host failover: You do not need to perform storage system tasks, such as suspending or
re-syncing a global-active device pair to recover from a host failure.
• Virtual machine migration: If a server is running a virtual machine creating a high load, you can move
the virtual machine to the host at the other site, which can access the
same data, so data migration between storage systems is unnecessary.
A global-active device environment can be implemented within a single site
or across two sites or three sites. Implementation across three sites provides the best protection against site failures because the primary, secondary, and quorum storage systems exist at different physical locations, or sites, as
shown in the following figure.Replicating volumes for continuous access277Hitachi Command Suite User Guide 
						

							In the figure above:
• The primary, secondary, and quorum storage systems are located across three sites, typically separated by short distances (campus) or
intermediate (metro) distances. Distance can affect the required path management software for hosts. The primary and secondary storage
systems must be VSP G1000 storage systems. The quorum storage system
monitoring the status of the primary and secondary storage can be any external storage system that supports virtualization of its volumes and is
physically connected using Fibre Channel or Fibre Channel over Ethernet (FCoE) to 'External' ports configured on the primary and secondary storagesystems. Supported external storage systems are identified, with theirrequired port attributes, in the  Hitachi Virtual Storage Platform G1000
Hitachi Universal Volume Manager User Guide .
• The HCS management servers are clustered across two sites in an active- standby configuration. The active node is used to manage both sites. The
standby node takes over site management if the active node fails. In
addition to Device Manager and Tiered Storage Manager, Replication
Manager is installed and licensed on both nodes for performing pair management tasks.
278Replicating volumes for continuous accessHitachi Command Suite User Guide 
						

							Note: In a global-active device environment, a single HCS management
server node should be used to discover the primary, secondary and
quorum storage systems, and the required hosts and pair management
servers at the primary and secondary sites. A complete view of resources
is required for HCS global-active device setup tasks, for allocating global-
active device pairs using the pair management servers, and for displaying
P-VOL/S-VOL I/O metrics in the Analytics tab.
If you discover resources by using separate management servers located
at the primary and secondary sites, you cannot use HCS to perform global-
active device setup tasks, or Device Manager to allocate global-active
device pairs. Instead, use Replication Manager for pair configuration and
pair management.
• Pair management servers are located at both the primary site and secondary site. Each pair management server must include Device
Manager Agent and Command Control Interface (CCI) to perform pair management tasks as directed by HCS, or directly from the pair
management server itself. Command devices (CMD) are used for
processing pair management commands. The primary and secondary site
pair management servers are used by the HCS management server for
global-active device pair operations.
• The application servers are clustered across two sites with HBA (Fibre Channel) paths to both storage systems. Application servers can be
configured in an active-standby or active-active cluster. In an active-active
cluster configuration both nodes can perform read-write I/O. Depending on
the multi-path software being used, an application server can use any
available path to access data, or will use the shortest available path if configured to do so, meaning an application server at the primary site
would read data from primary site storage, and an application server at
the secondary site would read data from secondary site storage. Write I/O
to global-active device pairs results in the same data being written to the
pair, regardless of which storage system and port the write I/O occurs on.
Data is always written to the primary volume first, then the secondary
volume using the physical remote path (MCU/RCU) connections for bi-
directional data transfers.
Note:  Hitachi Dynamic Link Manager (HDLM) provides features for
identifying non-preferred (longer) paths for I/O, ensuring the use of the shortest I/O path under normal conditions. If a path failure occurs, the
longer path is used for I/O. This optimizes I/O performance while retaining
high-availability. See the  Hitachi Command Suite Dynamic Link Manager
User Guide  for your host OS.Replicating volumes for continuous access279Hitachi Command Suite User Guide 
						

							If the host OS is HP-UX 11iv3 and you are using the native multi-pathing
features, execute the following command in advance to disable the multi-
pathing features for legacy device special files:
scsimgr save_attr -a leg_mpath_enable=false
The following workflow describes the necessary planning and implementation steps for creating, monitoring and managing a global-active device
environment.
280Replicating volumes for continuous accessHitachi Command Suite User Guide