Before you start configuring GDR, make sure that:
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All Nexsan iSeries have assigned IP addresses. |
|
All Nexsan iSeries have assigned Portals. |
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IP Routes have been defined. |
If you have not configured any of these, stop and do so now (refer to the Nexsan iSeries Manager User Manual). |
This chapter provides examples for Active/Passive configurations. |
Use Nexsan iSeries Manager GUI to configure your GDR solution. The following lists the basic steps for building a GDR solution:
1. |
Defining Primary and Secondary Sites |
2. |
Assigning Nexsan iSeries to Primary and Secondary sites |
3. |
Creating GDR Pairs A GDR pair is the combination of a designated primary volume for replication and a designated secondary volume that receives the replicated data. GDR pairs are created via the Create Pairs Wizard. The wizard guides you through the creation steps. At each stage in the create pairs process, you can either select previously existing volumes or create new ones. |
Defining Primary/Secondary Sites
The site wizard allows you to define sites for your GDR solution.
You must define two different sites before you can begin configuring DR. |
1. |
From the navigation pane, select Nexsan iSeries Manager > New > Site. |
2. |
From the Quick Launch:
Configure > Create System Entity > Site… |
The New Site dialog box opens
5. |
Repeat for each site in your GDR topology. |
Assign Nexsan iSeries to Primary/Secondary Sites
A site can be built from a stand-alone Nexsan iSeries or a Nexsan iSeries cluster. You must assign the Nexsan iSeries or Cluster to the primary/secondary sites.
You can assign as many storage resource groups as needed per site (A storage resource group is a cluster or a single Nexsan iSeries). |
Figure 2-3. Add Nexsan iSeries/Cluster
To add Nexsan iSeries to site(s):
1. |
From the Nexsan iSeries Manager menu, select Local/Remote site, right click and select New > Storage Resource Group [Single Switch] |
Figure 2-4. Add New Nexsan iSeries
2. |
Specify IP Address for new Nexsan iSeries. |
A cluster contains 2 Nexsan iSeries. After adding a cluster, you must add the 2 Nexsan iSeries to the defined cluster. |
To add new cluster to site(s):
1. |
From the Nexsan iSeries Manager menu, select Local/Remote site, right click and select New > Storage Resource Group [Cluster]. |
Figure 2-5. Add New Cluster
2. |
Specify new Cluster Alias. |
4. |
Add two Nexsan iSeries under cluster by following the steps for XAdding X. |
The Nexsan iSeries must be part of a site. If you don’t start from scratch with a new Nexsan iSeries, you can move an existing one to a site. |
A GDR pair is the combination of a designated primary volume for replication and a designated secondary volume that receives the replicated data. You may create Synchronous or Asynchronous pairs. The GDR Wizard guides you through the process.
Before you start configuring GDR, make sure that:
|
All Nexsan iSeries have assigned IP addresses. |
|
All Nexsan iSeries have assigned Portals. |
|
IP Routes have been defined. |
|
If you have not configured any of these, stop and do so now (refer to the Nexsan iSeries Manager User Manual). |
|
Starting the Create Pair Wizard
The wizard guides you through the steps for making GDR pairs. The wizard is flexible. You can either choose from previously existing volumes or create the necessary volumes. If no suitable volume exists, you must create one.
The following sections are written for both Synchronous and Asynchronous pairs. When something is specific to one type it is noted. |
To open the GDR Pair wizard:
1. |
From the Quick Launch:
GDR > Create Pair |
Figure 2-6. Create Pair Selected
Configuring Primary Site Parameters
The steps for configuring Primary Site/Secondary are the same, the only difference being the focus on the site. |
1. |
Select the pair’s primary Site. |
2. |
Select the pair’s Cluster/Nexsan iSeries. |
Figure 2-7. Select Primary Site & Cluster/Nexsan iSeries
If the Nexsan iSeries has configured volumes, the wizard will automatically discover and display them. The wizard also displays available storage.
a. |
Select an existing volume (exposed or unexposed). |
c. |
Create a new volume from existing storage and select it. |
Figure 2-8. Select Primary Volume
To create a new volume from existing storage and select it:
2. |
Select desired resource(s) and type of volume: Mirror, Stripe or Concatenation. Configure volume type parameters. Once volume has been created it appears on the right hand side of the window. |
Figure 2-9. Create New Volume
Configure Target Parameters
If the Nexsan iSeries has configured Targets, the wizard will automatically discover and display the previously configured target parameters.
Case 1: You selected an exposed Volume for your primary resource:
Figure 2-10. Select Target
Case 2: You selected an unexposed Volume for your primary resource:
1. |
If no Target exists, the Create New Target window appears. Create a target and configure desired parameters. |
2. |
Once a target exists, the wizard displays the available target parameters: Target alias, Target name and LUN. Select desired parameters or click New Target to create another target. |
1. |
Select pair type Synchronous/Asynchronous. |
Figure 2-11. Select Pair Type
Configure Initial Synchronization Policy and Consistency Group Parameters
1. |
Select the Initial Sync. Policy: |
None: The Primary Volume has just been created and there is no data on it to synchronize with the secondary.
Online: For previously existing Primary Volume containing data.
Offline: To copy data on external media.
Offline is available only for Asynchronous pairs. |
2. |
Configure Consistency Group parameters: Note: CG parameters are available only for Asynchronous pairs. |
Use existing: Select an existing Consistency Group name
New: Fill in name for new group
None: For stand-alone asynchronous pairs
Figure 2-12. Init. Sync Policy and Consistency Group Parameters
This section is relevant only for Asynchronous Pairs. |
1. |
Set the replication policy parameters. |
Figure 2-13. Replication Parameters
This section is relevant only for Asynchronous Pairs. |
The transfer policy will be the same as that chosen for replication unless otherwise configured. |
To set transfer policy parameters that are different from those selected for replication:
The Transfer Policy Parameters window appears (
XFigure 2-14X).
3. |
Set the transfer policy parameters. |
Figure 2-14. Transfer Policy Parameters
Configuring Secondary Site Parameters
This section is relevant only for Asynchronous Pairs. If you are configuring a Synchronous pair, skip to XReview GDR Pair SummaryX. |
There is only one Journal per Nexsan iSeries. If a journal was already defined, the screens in this section will not appear. Skip to the next section: XSnapshot VolumeX. |
Creating Primary Journal Volumes
If no journal volume exists the following screen appears.
Figure 2-15. Create Journal Volume
2. |
Select storage resource for journal volume or create volume for new resource. |
Figure 2-16. Select Storage Resource for Journal Volume
To create new storage resource for journal volume
2. |
Select desired resource(s) and type of volume: Mirror, Stripe or Concatenation. Configure volume type parameters. Once volume has been created it appears on the right hand side of the window. |
Building a journal on top of a Mirror volume is not supported. |
Figure 2-17. Create Storage Resource for Journal Volume
6. |
Enter the Journal threshold. The default threshold is 80%. |
When journal is filled with data exceeding its threshold, an alarm is displayed. |
Figure 2-18. Summary of Journal Volume
Creating Secondary Journal Volumes
This section is relevant only for Asynchronous Pairs. If you are configuring a Synchronous pair, skip to XReview GDR Pair SummaryX. |
1. |
If no snapshot volume exists, the following screen appears. |
Figure 2-19. No Snaphot Volume
Figure 2-20. Snaphot Volume for Primary Site
4. |
Create and select a snapshot volume for the secondary site. |
5. |
Set snapshot alias and threshold. |
Figure 2-21. Snapshot Parameters – Primary Site
The following screen appears asking if you want to create snapshot on the secondary site.
6. |
Click Yes (recommended for faster recovery time). |
Figure 2-22. Create Snapshot
Figure 2-23. Snaphot Volume for Secondary Site
8. |
Set snapshot Volume alias and Load threshold. |
Figure 2-24. Snapshot Parameters – Secondary Site
2. |
Click Apply to apply the GDR pair configurations. |
3. |
Click Yes if you want to create another Disaster Recovery pair. |
4. |
Click No if you are done. |
Figure 2-26. Create Another GDR Pair
After creating all your pairs or if you have made other substantial changes to the configuration, Nexsan recommends saving the database. For details, see XSaving StorgePro DatabaseX. |
Once you have configured your GDR setup (or after having recovered a site), you can start the initial synchronization of any volumes (already containing data) that you want to replicate to the secondary site. Start initial synchronization and replication for the pair, consistency group and site levels.
1. |
Select the entity level for replication: pair, consistency group or site. |
2. |
From the Quick Launch:
GDR > Start Replication |
Figure 2-27. Start Replication
3. |
Select the Consistency Group or the Pair for replication and click OK. |
Figure 2-28. Selecting Pair or CG for Replication
Initial synchronization and replication begins. You can view the progress of the initial synchronization replication.
4. |
From the Quick Launch:
GDR > Monitor GDR |
Figure 2-29. Monitor GDR Quick Launch
Figure 2-30. Replication Progress
Your GDR solution is now configured and all preliminary data to be replicated is replicating.
In the case of site fallback, after Initial sync has completed (indicated as 100% see
XFigure 2-30X), you can deactivate applications on the secondary site and fallback the secondary site back to the primary site. Once all write operations are stopped and all caches are flushed, PITs are taken of all GDR volumes and replicated to the primary site. When all PITs have been transferred you can switch back to the primary site.
When Offline is chosen for the type of Init Sync, a snapshot of the primary volume is created. This snapshot volume is copied to an external disk/tape. This separate tape/disk must be physically transferred to the secondary site. After being physically transferred, the data is copied to the secondary volume.
To copy data to external media and copy it to remote site:
1. |
Create a GDR pair in primary and secondary sites with policy Offline Sync. |
3. |
Expose primary snapshot to host. The host is the backup server that the external tape/media is connected to. |
4. |
Copy snapshot to tape/disk. Use “disk image” to copy all block to the tape/disk. |
5. |
Define the Journal on secondary site before starting replication. |
6. |
Start replication. All changes are replicated to the remote site journal waiting to be merged once the storage arrives. |
7. |
Physically move the tape/disk to the secondary host. |
8. |
Expose the secondary volume to the secondary host. |
9. |
Copy contents of tape/disk to secondary volume. |
10. |
Merge the changes from the journal. From the pair view window, select the pair, right click and select Init. Sync > End. |
Using Online Init Sync with Low Bandwidth Lines
This section describes the needed actions while performing Online Initial Sync to a secondary Nexsan iSeries connected to the same LAN as the primary Nexsan iSeries in case of low bandwidth.
To perform Online Initial Sync when there is low bandwidth:
1. |
Connect the secondary Nexsan iSeries locally to the LAN. |
2. |
Using the Create Pair Wizard, configure all pairs with Init Sync Type=Online. |
3. |
After all pairs have been created, start replication. |
Do the following once Initial Sync has finished:
1. |
Shut down and disconnect the locally attached Nexsan iSeries. |
2. |
Physically move the Nexsan iSeries to the remote site and connect it to the LAN. Turn on the power for the storage and the Nexsan iSeries. |
3. |
Configure the MGNT port on the remote Nexsan iSeries via the serial port or telnet to its new. |
4. |
If you are using a cluster in the secondary site you must remove the old neighbor on both Nexsan iSeries and define a new neighbor (with the new subnet) on both Nexsan iSeries. Do this via the serial port using the CLI command: neighbor>remove -nb name |
5. |
Using the Nexsan iSeries Manager GUI, delete the old portal and delete the portal IP on the remote Nexsan iSeries. |
6. |
Add the new IP and the portal for the remote site on the remote Nexsan iSeries. |
7. |
On the remote Nexsan iSeries, configure the routing to the local site. |
8. |
On the local Nexsan iSeries, configure the routing to the remote site. |
9. |
On the local Nexsan iSeries, delete the old remote portal for the remote targets. |
10. |
On the local Nexsan iSeries, configure the new remote portal for the remote targets. |
For more information on deleting portal see
Portals in Chapter 3. iSeries Manager GUI User Manual.For more information on how to add an IP Address see
IP Address in Chapter 3. iSeries Manager GUI User Manual. For more information on how to add an IP Address see
IP Routing in Chapter 3. iSeries Manager GUI User Manual.Saving StorgePro Database
Nexsan recommends saving the database after making substantial changes to your configuration. In the event that the system crashes, you can import the Nexsan iSeries Manager database. Nexsan recommends that you save the database on the secondary site.
To export the database to a file:
1. |
From the File menu select Export… |
Figure 2-31. Export Nexsan iSeries Manager Database
The Export window appears.
Figure 2-32. Select Location
2. |
Select location for the file spconfig.zip. Nexsan recommends keeping this file in an external safe place (e.g. removable disk). If the local site goes down, you need to be able to access this file. |
To import the saved database:
1. |
From the File menu select Import… |
2. |
Select the file spconfig.zip. |
The file will be imported.
