When backing up to a deduplication storage appliance from Veeam Backup & Replication, performance or deduplication ratio is low without using best practice settings. 




The default options of Veeam Backup & Replication are intended for non-deduplication storage.

If you use deduplication storage systems, you need to additionally configure the backup architecture and Veeam settings to achieve best performance. Below are some hardware and software configuration options that can be used with deduplication storages. In some cases, you may need to combine more than one option, but in all cases, it is strongly encouraged that you consult your deduplication appliance vendor and/or a value added reseller to discuss individual needs.

For the general architecture planning, Veeam’s best practices is to follow the industry 3-2-1 backup rule:

3: Maintain at least three copies of your data and applications. That’s the one copy you’re using and two backups. This way, if one of your backups is unavailable for any reason (for example, if you store the backup in the same locations with the copy you use and both go down), you can still recover what you need.

2: Store your backups on at least two different types of media or storage controller logics. One reason for this is that each type of media has its own vulnerabilities, and you don’t want both of your backups susceptible to the same problem.

For example: run your business on a general purpose fast storage system and store your backups on a storage system that is specialized for this purpose, or a separate server with local disks.

1: Keep one of the backups in a different location. Consider a crisis in your primary data center, such as a fire or power failure. If all your copies are collocated, they can all be affected, taking down your organization.


General Deduplication Storage Best Practices


Step 1:  Creating backups on the first site with long term retention.

Use a backup target storage system (general purpose storage system) for short-term primary backups and instruct Veeam to copy the backups to a deduplication storage system for long-term retention.

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A variant of this approach is to use a standard server with battery backed RAID controller and disks to store the primary backups (cache approach) and use backup copy to deduplication storage systems for long-term etention.

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Step 2: Add offsite target.

In addition to the above scenarios, you can use the following options to create an offsite copy of your data.


1. Place a deduplication storage at the second site. Use Veeam backup copy job to create the secondary offsite backup from the primary backup.  
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2. Place a deduplication storage on both sides:  
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3. Place a deduplication storage on primary side and use object storage or tape on second site. Use Veeam backup to tape jobs or Veeam scale-out backup repository cloud tier (connection to object storages) to store data offsite.
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The scenario above reflects general best practices. Please contact your deduplication storage vendor for further guidance and check the vendor links provided above for additional usable scenarios with the specific storage.

Best Practices For Deduplication Storage Systems


Backup Chains

Veeam offers a wide range of backup chains but for deduplication storages the following are recommended:

  • General Deduplication Storages + Backup Copy Job That Reads From Source Backup Chain (Exagrid, Quantum DXi, Infinidat InfiniGuard and Fujitsu Eternus CS800):
To optimize the deduplication storage performance, select at least one GFS restore point (weekly backup is mandatory for deduplication storages). Enable the “Read the entire restore point from source backup instead of synthesizing it from increments” option to avoid creating synthetic restore points from the deduplication storage (data rehydration). 
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  •  HPE StoreOnce Catalyst / Dell EMC DataDomain DDboost  + Copy Over WAN + Backup Copy Job:

The previous described option provides fast processing in situations that do not involve transport over WAN links. Also, optimized integration with Catalyst and Dell EMC DDBoost allows using synthetic processing. For these environments uncheck the “Read the entire restore point from source backup instead of synthesizing it from increments” but leave the weekly GFS backup enabled.
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  • Special Scenarios Based on Vendor Own Guidelines + Backup Job With Active Full or Synthetic Full Backup:
The above vendor best practices and design guides mention situations where a deduplication storage can be used as primary backup target. Depending on the guidelines, select the incremental backup mode with active or synthetic full backup.
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Inline Deduplication

Disable inline deduplication setting when writing into deduplication storages.

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However for deduplication devices that have a non deduplicated landing zone (Like ExaGrid) and backup only VMs, you can save some space: to do this, enable inline deduplication

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By default, the Veeam source DataMover (Veeam Proxy or Agent) compression level is set to “optimal” to reduce data that needs to be transported over the network. The repository or the gateway server uncompress the data before storing the data to the deduplication device.

For backup copy jobs, set the compression level to “Auto” to leave the data in the way it was stored originally on the primary backup target.

For deduplication devices that have a non deduplicated landing zone (Like ExaGrid) and backup only VMs, you can save some space: to do this, set the compression level to “Dedup Friendly” and uncheck the “Decompres backup data blocks before storing” option.

The general best practices are:

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Block Size

Veeam can use different block sizes to store backups on the target. The block size is defined in the backup job settings and will be kept across all copies. Non-VM backups settings are set to “Local Target” automatically, and the size can not be modified.

Block size changes are only activated by an active full and will only be used for the new backup chains (the data stored already are not touched).

Only 2 of the block size settings are recommended for deduplication storage usage at VM backups:

  • Storage optimization: Local target (large blocks)
Use this option for any general deduplication storage / HPE StoreOnce Catalyst / Dell EMC DataDomain DDboost / Quantum DXi. 
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  • Storage optimization: Local target 

Use this option for ExaGrid.
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Block Alignment

By default, this advanced repository setting is disabled. Enable it for deduplication storages that work with fixed block length deduplication (e.g. NetApp ONTAP deduplication) or in situations where you can use ReFS/XFS Fast Cloning.


Encryption will create random data at the backup targets; as a result, the deduplication storages will not work effectively. It is recommended not to use encryption with deduplication storages.

Health Check

Health check reads all data from the last restore point and across the backup chain. When used with deduplication storages, this data is rehydrated from the storage which may cause slow process. It is recommended to enable health check on the primary backup job before data is transported by backup copy job to a deduplication storage.

Veeam Defragmentation And Compact Settings

If you followed the above described guidelines, you do not need these settings. It is recommended that you disable them.