Sun Cluster Geographic Edition System Administration Guide

Activating Hitachi TrueCopy Protection Group

When you activate a protection group, the protection group assumes the role that you assigned to it during configuration. You can activate a protection group in the following ways:

Globally, meaning you activate a protection group on both clusters where the protection group is configured.
On the primary cluster only, so that the secondary cluster remains inactive.
On a secondary cluster only, when it remains inactive on the primary cluster.

Activating a Hitachi TrueCopy protection group on a cluster has the following impact on the data replication layer:

The data replication configuration of the protection group is validated. During validation, the protection group's current local role is compared with the aggregate device group state as described in Table 10–3. If validation is successful, data replication is started.
Data replication is started on the data replication device groups that are configured for the protection group, no matter whether the activation occurs on a primary or secondary cluster. Data is always replicated from the cluster on which the protection group's local role is primary to the cluster on which the protection group's local role is secondary.

Application handling proceeds only after data replication has been started successfully.

Activating a protection group has the following impact on the application layer:

When a protection group is activated on the primary cluster, the application resource groups that are configured for the protection group are also started.
When a protection group is activated on the secondary cluster, the application resource groups are not started.

The Hitachi TrueCopy command used to start data replication depends on the following factors:

Aggregate device group state
Local role of the protection group
Current pair state

The following table describes the Hitachi TrueCopy command used to start data replication for each of the possible combinations of factors. In the commands, dg is the device group name and fl is the fence level configured for the device group.

Table 10–4 Commands Used to Start Hitachi TrueCopy Data Replication


Aggregate Device Group State	Valid Local Protection Group Role	Hitachi TrueCopyStart Command
`SMPL`	`primary` or `secondary`	`paircreate -vl -g dg -f fl` `paircreate -vr -g dg -f fl` Both commands require that the `horcmd` process is up on the remote cluster.
`Regular Primary`	`primary`	If the local state code is 22, 23, 25, 26, 29, 42, 43, 45, 46, or 47, no command is issued because data is already being replicated. If the local state code is 24, 44, or 48, then the following command is issued: `pairresync -g dg [-l]` If the local state code is 11, then the following command is issued: `paircreate -vl -g dg -f fl` Both commands require that the `horcmd` process is up on the remote cluster.
`Regular Secondary`	`secondary`	If the local state code is 32, 33, 35, 36, 39, 52, 53, 55, 56, or 57, no command is issued because data is already being replicated. If the local state code is 34, 54, or 58, then the following command is issued: `pairresync -g dg` If the local state code is 11, the following command is issued: `paircreate -vr -g dg -f fl` Both commands require that the `horcmd` process is up on the remote cluster.
`Takeover Primary`	`primary`	If the local state code is 34 or 54, the following command is issued: `pairresync -swaps -g` If the local state code is 11, then the following command is issued: `paircreate -vl -g dg -f fl` The `paircreate` command requires that the `horcmd` process is up on the remote cluster.
`Takeover Secondary`	`secondary`	If the local state code is 24, 44, 25, or 45, the following command is issued: `pairresync -swapp -g dg` If the local state code is 11, the following command is issued: `paircreate -vr -g dg -f fl` Both commands require that the `horcmd` process is up on the remote cluster.

How to Activate a Hitachi TrueCopy Protection Group

Steps

Log in to one of the cluster nodes.

You must be assigned the Geo Management RBAC rights profile to complete this procedure. For more information about RBAC, see Sun Cluster Geographic Edition Software and RBAC.

Activate the protection group.

When you activate a protection group, its application resource groups are also brought online.
# geopg start -e scope [-n] protection-group-name
-e scope

Specifies the scope of the command

If the scope is Local, then the command operates on the local cluster only. If the scope is Global, the command operates on both clusters that deploy the protection group.

Note –
The property values, such as Global and Local, are not case sensitive.

-n

Prevents the start of data replication at protection group startup

If you omit this option, the data replication subsystem starts at the same time as the protection group.

protection-group-name

Specifies the name of the protection group

The geopg start command uses the scswitch -Z -g resource-groups command to bring resource groups and resources online. For more information about using this command, see the scswitch(1M) man page.

Example 10–16 How the Sun Cluster Geographic Edition Software Issues the Command to Start Replication

The following example illustrates how the Sun Cluster Geographic Edition determines the Hitachi TrueCopy command used to start data replication.

First, the Hitachi TrueCopy protection group is created.

phys-paris-1# geopg create -s paris-newyork-ps -o primary -d truecopy tcpg

A device group, devgroup1, is added to the protection group.

phys-paris-1# geopg add-device-group -p fence_level=async devgroup1 tcpg

The current state of a Hitachi TrueCopydevice group, devgroup1, is given 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..SMPL ----  ----, ----- ----   - 
devgroup1 pair1(R) (CL1-C , 0, 20)54321 609..SMPL ----  ----, ----- ----   - 
devgroup1 pair2(L) (CL1-A , 0, 2) 12345   2..SMPL ----  ----, ----- ----   - 
devgroup1 pair2(R) (CL1-C , 0,21) 54321 610..SMPL ----  ----, ----- ----   -

The aggregate device group state is SMPL.

Next, the protection group, tcpg, is activated by using the geopg start command.

phys-paris-1# geopg start -e local tcpg

The Sun Cluster Geographic Edition software executes the paircreate -g devgroup1 -vl -f async command at the data replication level. If the command is successful, the state of devgroup1 is given 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 COPY ASYNC,54321  609   - 
devgroup1 pair1(R) (CL1-C , 0, 20)54321 609..S-VOL COPY ASYNC,-----   1    - 
devgroup1 pair2(L) (CL1-A , 0, 2) 12345   2..P-VOL COPY ASYNC,54321  610   - 
devgroup1 pair2(R) (CL1-C , 0,21) 54321 610..S-VOL COPY ASYNC,-----   2    -

Example 10–17 Activating a Hitachi TrueCopy Protection Group Globally

The following example illustrates how to activate a protection group globally:

# geopg start -e global tcpg

The protection group, tcpg, is activated on both clusters where the protection group is configured.

Example 10–18 Activating a Hitachi TrueCopy Protection Group Locally

The following example illustrates how to activate a protection group on a local cluster only. This local cluster might be a primary cluster or a secondary cluster, depending on the cluster's role.

# geopg start -e local tcpg