Storage Migration with Double-Take Availability

Storage Migration with Double-Take Availability


This is a demonstration of how Double-Take Availability migrates data from an EMC-based volume to an EqualLogic based-volume.


In some circumstances, a customer may want to update their storage from EMC to EqualLogic storage without necessarily migrating the server itself. This article focuses on this scenario.
Double-Take Availability works at the Operating System level and allows the user to synchronize data from one volume to another from within the confines of the OS. This article focuses on a source volume being an EMC-based volume and the target volume an EqualLogic-based volume. Double-Take is however agnostic of the underlying storage. So, the information contained in this demonstration also applies for other storage types (ie: migrating from non-Dell storage to Dell storage, MDxx storage to EQL storage, EMC storage to Compellent storage, and so on…)
Additionally, you should note that storage can be local (DAS), or SAN-attached to the server. This example of EMC-EQL represents an EMC Fibre-attached volume and an EQL iSCSI attached volume.
To summarize, Double-Take Availability will replicate/mirror data from/to volumes where those volumes are considered physical logical drives to the Windows OS that Double-Take is installed to. The volumes can be local/direct attached, Fibre-attached, or iSCSI attached.
Double-Take Availability provides two mechanisms to achieve data migration from volume to volume.
1) Data synchronization and replication from drive-to-drive.
2) Failover of Windows Shared folders (if applicable)

Data synchronization and replication from drive-to-drive
Double-Take can replicate individual files, folders or all files and folders on a volume. Replication is byte-level and asynchronous. NTFS permissions/ACLs are captured and replicated as part of the replication process as well as the file/folder structure of the data.

Failover of Windows Shared folders (if applicable)
In addition to data synchronization and replication, Double-Take Availability can capture and replicate the Windows Shared folders from a protected volume and apply the Shares to the target destination volume. This process is considered "failover" and is managed via the Double-Take Failover Control Center.

Source Server / Volumes

We have a Dell R710 PowerEdge server running Windows 2008 R2 Enterprise.
C:\ contains the Operating System and other System-State (Program Files, User Profiles, etc)
H:\ is an EMC-based volume. It is attached to the server using Fibre channel via a HBA.
The data on this volume will be migrated to the EQL-based volume.
G:\ is the EQL-based volume… a PS6000XV device. It is attached to the server using iSCSI via iSCSI Initiator.

Target Server

There is no separate target server for this demonstration, as we are moving data volume-to-volume on the same server. The source server is therefore both a source and target.


Please take a moment to view the following video. It is a live demonstration of the data migration process.
The video walks through the process of configuring Double-Take Availability for the data migration.

YouTube Video : Storage Migration with Double-Take Availability

Migrating Windows Shares
If you have Windows Shares that you would like to retain following a data migration, you will need to apply an additional step to the data replication.

Prior to cutting over to the new volume.

Steps a-f should be configured while replication and/or mirroring is occurring and prior to disconnecting the Double-Take Replication set connection.
a) Open Double-Take "Failover Control Center"
This can be accessed from the Replication Console via the TOOLS menu.
b) With Failover Control Center open, select "Add Target" and add the server name/IP address.
c) Select "Add Monitor". This will launch a "Monitor Settings" window.
d) Select the server.
e) You will see various options on the right side of the window. You are primarily concerned with "Items to Failover". Deselect "IP Address(es)" and also deselect "Server Name".
Ensure "Share(s)" is selected.
You will also see a "Failover Processing" section. Ensure "Manual Intervention" and "Use .SHR mapping file" are both selected.
Finally, there is an "Active Directory" section. Ensure the options are deselected within this category.
Click "Apply"/OK to this screen. At this time you have configured failover, for Windows Shares only, because we are not failing over server to server.
f) You will be returned to the main Failover Control Center window. Select "Update Shares".

Post-volume/drive cutover

Once you have followed the steps of disconnecting Double-Take replication and have re-mapped the drive letter(s) to the new volume(s) per the video demonstration, you can re-implement the Windows Shares by selecting "Failover" in the Double-Take Failover Control Center.


When you have a need to migrate data from one volume to another, Double-Take Availability makes the process very easy, providing a means to migrate data between dissimilar storage.
When you are adding a new volume/drive to a server and want a way to synchronize some of the files or all of the data from an existing volume, Double-Take provides the granularity to achieve this with minimal downtime. Additionally, should you have any Windows Shares to port from volume to volume, Double-Take Availability can replicate those Shares for you.

Article ID: SLN310441

Last Date Modified: 08/14/2018 03:42 AM

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