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Oracle Solaris Cluster Geographic Edition Data Replication Guide for Hitachi TrueCopy and Universal Replicator |
1. Replicating Data With Hitachi TrueCopy and Universal Replicator Software
2. Administering Hitachi TrueCopy and Universal Replicator Protection Groups
Strategies for Creating Hitachi TrueCopy and Universal Replicator Protection Groups
Creating a Protection Group While the Application Is Offline
Creating a Protection Group While the Application Is Online
Ensuring Data Consistency for Hitachi Universal Replicator in Asynchronous Mode
Understanding Data Consistency in Geographic Edition
Using Consistency Group IDs to Ensure Data Consistency
Requirements to Support Oracle Real Application Clusters With Data Replication Software
How to Create a Protection Group for Oracle Real Application Clusters
How the Data Replication Subsystem Validates the Device Group
How to Modify a Hitachi TrueCopy or Universal Replicator Protection Group
Validating a Hitachi TrueCopy or Universal Replicator Protection Group
How to Validate a Hitachi TrueCopy or Universal Replicator Protection Group
How to Delete a Hitachi TrueCopy or Universal Replicator Protection Group
Administering Hitachi TrueCopy and Universal Replicator Application Resource Groups
Administering Hitachi TrueCopy and Universal Replicator Data Replication Device Groups
Validations Made by the Data Replication Subsystem
How the State of the Hitachi TrueCopy or Universal Replicator Device Group Is Validated
Determining the State of an Individual Hitachi TrueCopy or Universal Replicator Device Group
Determining the Aggregate Hitachi TrueCopy or Universal Replicator Device Group State
Validating the Local Role of the Protection Group Against the Aggregate Device Group State
How to Modify a Hitachi TrueCopy or Universal Replicator Data Replication Device Group
Activating a Hitachi TrueCopy or Universal Replicator Protection Group
How to Activate a Hitachi TrueCopy or Universal Replicator Protection Group
Deactivating a Hitachi TrueCopy or Universal Replicator Protection Group
How to Deactivate a Hitachi TrueCopy or Universal Replicator Protection Group
Resynchronizing a Hitachi TrueCopy or Universal Replicator Protection Group
How to Resynchronize a Protection Group
Checking the Runtime Status of Hitachi TrueCopy and Universal Replicator Data Replication
Displaying a Hitachi TrueCopy or Universal Replicator Runtime Status Overview
How to Check the Overall Runtime Status of Replication
Displaying a Detailed Hitachi TrueCopy or Universal Replicator Runtime Status
3. Migrating Services That Use Hitachi TrueCopy and Universal Replicator Data Replication
A. Geographic Edition Properties for Hitachi TrueCopy and Universal Replicator
This section provides the following information about administering Hitachi TrueCopy and Universal Replicator data replication device groups:
How the State of the Hitachi TrueCopy or Universal Replicator Device Group Is Validated
How to Modify a Hitachi TrueCopy or Universal Replicator Data Replication Device Group
For details about configuring a Hitachi TrueCopy or Universal Replicator data replication protection group, see How to Create and Configure a Hitachi TrueCopy or Universal Replicator Protection Group That Does Not Use Oracle Real Application Clusters.
You must be assigned the Geo Management RBAC rights profile to complete this procedure. For more information about RBAC, see Geographic Edition Software and RBAC in Oracle Solaris Cluster Geographic Edition System Administration Guide.
This command adds a device group to a protection group on the local cluster and propagates the new configuration to the partner cluster if the partner cluster contains a protection group of the same name.
# geopg add-device-group -p property [-p...] devicegroupname protectiongroupname
Specifies the properties of the data replication device group.
You can specify the Fence_level property which defines the fence level that is used by the device group. The fence level determines the level of consistency among the primary and secondary volumes for that device group.
You can set this property to data, status, never, or async. When you use a Fence_level of never or async, the application can continue to write to the primary cluster even after failure on the secondary cluster. However, when you set the Fence_level property to data or status, the application on the primary cluster might fail because the secondary cluster is not available for the following reasons:
Data replication link failure
Secondary cluster and storage is down
Storage on the secondary cluster is down
Caution - To avoid application failure on the primary cluster, specify a Fence_level of never or async. If you specify a Fence_level of never, the data replication roles do not change after you perform a takeover. If you have special requirements to use a Fence_level of data or status, consult your Oracle representative. |
The other properties you can specify depend on the type of data replication you are using. For details about these properties, see Appendix A, Standard Geographic Edition Properties, in Oracle Solaris Cluster Geographic Edition System Administration Guide.
Specifies the name of the new data replication device group.
Specifies the name of the protection group that will contain the new data replication device group.
For information about the names and values that are supported by Geographic Edition software, see Appendix B, Legal Names and Values of Geographic Edition Entities, in Oracle Solaris Cluster Geographic Edition System Administration Guide.
For more information about the geopg command, refer to the geopg(1M) man page.
Example 2-11 Adding a Data Replication Device Group to a Hitachi TrueCopy or Universal Replicator Protection Group
This example creates a Hitachi TrueCopy or Universal Replicator data replication device group in the tcpg protection group.
# geopg add-device-group -p Fence_level=data devgroup1 tcpg
When the Hitachi TrueCopy or Universal Replicator device group, configured as dev_group in the /etc/horcm.conf file, is added to a protection group, the data replication layer makes the following validations.
Validates that the horcmd daemon is running on at least one node in the Nodelist property of the protection group.
Checks that the path to the storage device exists from all the nodes that are specified in the Nodelist property. The storage device controls the new Hitachi TrueCopy or Universal Replicator device group.
The Hitachi TrueCopy and Universal Replicator device group properties that are specified in the geopg add-device-group command are validated as described in the following table.
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When a Hitachi TrueCopy or Universal Replicator device group is added to a protection group, a Oracle Solaris Cluster resource is automatically created by this command. This resource monitors data replication. The name of the resource is r-tc-protectiongroupname-devicegroupname. This resource is placed in the corresponding Oracle Solaris Cluster resource group, which is named rg-tc-protectiongroupname.
Caution - You must use caution before you modify these replication resources with Oracle Solaris Cluster commands. These resources are for internal implementation purposes only. |
For validation purposes, Geographic Edition gives each Hitachi TrueCopy or Universal Replicator device group a state according to the current state of its pair. This state is returned by the pairvolchk -g devicegroup -ss command.
The remainder of this section describes the individual device group states and how these states are validated against the local role of the protection group.
An individual Hitachi TrueCopy or Universal Replicator device group can be in one of the following states:
SMPL
Regular Primary
Regular Secondary
Takeover Primary
Takeover Secondary
The state of a particular device group is determined by using the value that is returned by the pairvolchk -g devicegroup -ss command. The following table describes the device group state associated with the values returned by the pairvolchk command.
Table 2-1 Individual Hitachi TrueCopy and Universal Replicator Device Group States
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If a protection group contains only one Hitachi TrueCopy or Universal Replicator device group, then the aggregate device group state is the same as the individual device group state.
When a protection group contains multiple Hitachi TrueCopy or Universal Replicator device groups, the aggregate device group state is obtained as described in the following table.
Table 2-2 Conditions That Determine the Aggregate Device Group State
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The aggregate device group state cannot be obtained for any other combination of individual device group states. This is considered a pair-state validation failure.
The local role of a Hitachi TrueCopy or Universal Replicator protection group is validated against the aggregate device group state as described in the following table.
Table 2-3 Validating the Aggregate Device Group State Against the Local Role of a Protection Group
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Example 2-12 Validating the Aggregate Device Group State
This example validates the state of a Hitachi TrueCopy or Universal Replicator device group against the role of the Hitachi TrueCopy or Universal Replicator protection group to which it belongs.
First, the protection group is created as follows:
phys-paris-1# geopg create -s paris-newyork-ps -o primary -d truecopy tcpg
A device group, devgroup1, is added to the protection group, tcpg, as follows:
phys-paris-1# geopg add-device-group -p fence_level=async devgroup1 tcpg
The current state of a Hitachi TrueCopy or Universal Replicator device group, devgroup1, is provided in the output of the pairdisplay command as follows:
phys-paris-1# pairdisplay -g devgroup1 Group PairVol(L/R) (Port#,TID,LU),Seq#,LDEV#,P/S,Status,Fence,Seq#,P-LDEV# M devgroup1 pair1(L) (CL1-A , 0, 1) 12345 1..P-VOL PAIR ASYNC,54321 609 - devgroup1 pair1(R) (CL1-C , 0, 20)54321 609..S-VOL PAIR ASYNC,----- 1 - devgroup1 pair2(L) (CL1-A , 0, 2) 12345 2..P-VOL PAIR ASYNC,54321 610 - devgroup1 pair2(R) (CL1-C , 0,21) 54321 610..S-VOL PAIR ASYNC,----- 2 -
The pairvolchk -g <DG> -ss command is run and returns a value of 23.
phys-paris-1# pairvolchk -g devgroup1 -ss parivolchk : Volstat is P-VOL.[status = PAIR fence = ASYNC] phys-paris-1# echo $? 23
The output of the pairvolchk command is 23, which corresponds in Table 2-1 to an individual device group state of Regular Primary. Because the protection group contains only one device group, the aggregate device group state is the same as the individual device group state. The device group state is valid because the local role of the protection group, specified by the -o option, is primary, as specified in Table 2-3.
You must be assigned the Geo Management RBAC rights profile to complete this procedure. For more information about RBAC, see Geographic Edition Software and RBAC in Oracle Solaris Cluster Geographic Edition System Administration Guide.
This command modifies the properties of a device group in a protection group on the local cluster. Then the command propagates the new configuration to the partner cluster if the partner cluster contains a protection group of the same name.
# geopg modify-device-group -p property [-p...] TCdevicegroupname protectiongroupname
Specifies the properties of the data replication device group.
For more information about the properties you can set, see Appendix A, Standard Geographic Edition Properties, in Oracle Solaris Cluster Geographic Edition System Administration Guide.
Specifies the name of the new data replication device group.
Specifies the name of the protection group that will contain the new data replication device group.
Example 2-13 Modifying the Properties of a Hitachi TrueCopy or Universal Replicator Data Replication Device Group
This example modifies the properties of a data replication device group that is part of a Hitachi TrueCopy or Universal Replicator protection group.
# geopg modify-device-group -p fence_level=async tcdg tcpg
Before You Begin
You might delete a data replication device group from a protection group if you added a data replication device group to a protection group. Normally, after an application is configured to write to a set of disks, you would not change the disks.
Deleting a data replication device group does not stop replication or change the replication status of the data replication device group.
For information about deleting protection groups, refer to How to Delete a Hitachi TrueCopy or Universal Replicator Protection Group. For information about deleting application resource groups from a protection group, refer to How to Delete an Application Resource Group From a Hitachi TrueCopy or Universal Replicator Protection Group.
You must be assigned the Geo Management RBAC rights profile to complete this procedure. For more information about RBAC, see Geographic Edition Software and RBAC in Oracle Solaris Cluster Geographic Edition System Administration Guide.
This command removes a device group from a protection group on the local cluster. Then the command propagates the new configuration to the partner cluster if the partner cluster contains a protection group of the same name.
# geopg remove-device-group devicegroupname protectiongroupname
Specifies the name of the data replication device group
Specifies the name of the protection group
When a device group is deleted from a Hitachi TrueCopy or Universal Replicator protection group, the corresponding Oracle Solaris Cluster resource, r-tc-protectiongroupname-devicegroupname, is removed from the replication resource group. As a result, the deleted device group is no longer monitored. The resource group is removed when the protection group is deleted.
Example 2-14 Deleting a Replication Device Group From a Hitachi TrueCopy or Universal Replicator Protection Group
This example removes a Hitachi TrueCopy or Universal Replicator data replication device group.
# geopg remove-device-group tcdg tcpg