Backup Exec’s deduplication license offers you three different flavors of deduplication: Server-side dedupe, client-side dedupe and appliance dedupe. The latter is the one I want to give you a closer look today. To can find more details regarding deduplication with Backup Exec in my post Backup Exec and Deduplication.
In order to use appliance deduplication you need three things: A Backup Exec license, a deduplication option and a storage that supports the Open Storage Technology (OST) for integration into Veritas’ backup products.
First of all, you have to create a storage volume within the appliance and publish it by the appliances OST interface. Next, you’ll have to install the OST plug-in provided by your appliance’s vendor on the Backup Exec server and restart the Backup Exec services afterwards, if the installation of the plug-in doesn’t require a reboot of the server anyway.
Afterwards you can create a new storage in Backup Exec by using the “Add Storage” wizard on the “Storage” page of the software. You’ll find the OST devices within “Network Storage”.
The exact steps to add your storage to Backup Exec differ from vendor to vendor, so I recommend referring to their step-by-step documentation:
EMC Data Domain: EMC ® Data Domain ® Boost for OpenStorage
Fujitsu Eternus CS800: ETERNUS CS800 S3 Backup Exec OST Guide
HP StoreOnce: Protecting server data with Backup Exec 15 and HP StoreOnce appliances (The link is not available at the moment)
Quantum DXi: DXi-Series Configuration and Best Practices Guide For Backup Exec from Symantec™
When the storage is set up, you’ll have to restart the Backup Exec services in order to bring the device online.
Now you can use the device the same way that you’d use a classic backup-to-disk storage.
Even though OST appliances store the backed up data on disks, they are treated like tape devices within Backup Exec. This means that single item restores from GRT enabled backups have to be staged to a local disk storage on the backup server. Therefore you’ll have to provide enough free disk space on the backup server to temporarily save the backup sets to during restores.
Using Optimized Duplication with OST Appliances
So far, so good.
The funny part starts, when you want to use the Optimized Duplication feature from Backup Exec with OST appliances to replicate (or duplicate, as Veritas calls it) the backed up data to a second site for disaster recovery purposes.
In order to do so, you’ll need a second set of the hardware and software described above: a backup server, a Backup Exec license, a deduplication license and, of course, another OST appliance. In addition to this, you have to purchase the so-called “Enterprise Server Option” for Backup Exec that includes, among others, the “Central Administration Server Option” (CASO). This is required for sharing storages between Backup Servers.
In order to simplify the licensing of your backup environment, I recommend using the Backup Exec capacity licensing model which includes all agents and options in unlimited numbers.
After declaring one of the backup servers as the Central Admin Server (CAS) by simply ticking the option within the setup wizard, you can add the other server(s) as Managed Backup Exec Server (MBES) to the configuration. You’ll then see them showing up in the Storage page of the CAS’s Backup Exec GUI. From here you can then start adding the OST appliance on the remote site to the remote MBES. When it is online, yu can do a right-click on its entry in the CAS’s GUI and select “Share” from the context menu. This will open a dialog where you can select, which servers shall be allowed to use the storage device. Please add the CAS here and restart its Backup Exec services after when you’re asked to do so.
When the services are up and running again, you can now simply create backup jobs on the CAS that back up data to the CAS’s OST appliance and add a duplication stage to the job where you select the OST appliance from the MBES as storage. This way, Backup Exec automatically detects, which blocks need to be sent to the MBES and transfers only those, without having the need to re-hydrate the data first.
For this to work, you need to configure the network adapters inside the OST appliances in a way that they can “see” each other. If you forget to do this, the duplication jobs will fail, even though the backup servers can connect to each other.