Dell Data Domain
You can use Dell Data Domain storage systems with Data Domain Boost (DD Boost) as backup repositories.
To support the DD Boost technology, Veeam Backup & Replication leverages the following Dell Data Domain components:
- DD Boost library. The DD Boost library is a component of the Dell Data Domain system. The DD Boost library is embedded into the Veeam Data Mover setup. When you add a Microsoft Windows server to the backup infrastructure, the DD Boost Library is automatically installed on the added server together with Veeam Data Mover.
- DD Boost server. The DD Boost server is a target-side component. The DD Boost server runs on the OS of the Dell Data Domain storage system.
To communicate with Dell Data Domain, Veeam Backup & Replication uses two Veeam Data Movers that are responsible for data processing and transfer:
- Veeam Data Mover on the backup proxy
- Veeam Data Mover on the gateway server
The Dell Data Domain storage cannot host Veeam Data Mover. For this reason, to communicate with the Dell Data Domain storage, you need to deploy a gateway server. Veeam Backup & Replication will automatically deploy Veeam Data Mover on this gateway server. For more information, see Gateway Server.
When any job addresses the backup repository, Veeam Data Mover on the gateway server establishes a connection with Veeam Data Mover on the backup proxy, enabling efficient data transfer over LAN or WAN.
You define what gateway server to use when you assign a backup repository role to Dell Data Domain. You can define the gateway server explicitly or instruct Veeam Backup & Replication to select it automatically.
For Dell Data Domain storage systems working over Fibre Channel, you must explicitly define the gateway server that will communicate with Dell Data Domain. As a gateway server, you must use a Microsoft Windows server that is added to the backup infrastructure and has access to Dell Data Domain over Fibre Channel.
Veeam Backup & Replication supports Dell Data Domain storage systems working over the following protocols:
- TCP/IP protocol: Veeam Backup & Replication communicates with the Dell Data Domain server by sending commands over the network.
- Fibre Channel protocol: Veeam Backup & Replication communicates with the Dell Data Domain Fibre Channel server by sending SCSI commands over Fibre Channel.
Limitations and Recommendations for Dell Data Domain
If you plan to use Dell Data Domain as a backup repository, consider the following limitations and recommendations:
- We strongly recommend that you follow recommendations from this list and also recommendations from this Veeam KB article.
Since Veeam Backup & Replication version 12, deduplicating storage appliances use the TLS connection. You can disable the TLS connection with a registry value for the deduplicating storage appliances that do not support the TLS connection. For more information, see this Veeam KB article.
- Use of Dell Data Domain with DD Boost does not guarantee improvement of job performance. It reduces the load on the network and improves the network throughput.
- NFS services must be enabled on Dell Data Domain. Otherwise, Veeam Backup & Replication will not be able to access the storage system.
- Do not enable encryption for the jobs targeted at the deduplication storage appliance. Encryption has a negative effect on the deduplication ratio. For more information, see Data Encryption.
Encryption can also affect the backup size: the size of a backup can be larger than the size of the original VM. When you enable encryption, set data processing block size to 4 MB, and leave decompression on target and block alignment enabled (enabled by default), the size of the backup increases by 1 MB for each 4 MB data block. This is because Veeam Backup & Replication reads blocks of 4 MB, encrypts them, adds 16 KB metadata to each data block and then aligns data blocks. This results in that each 4 MB data block on the source becomes 5 MB block on the target.
- When you create a backup job targeted at an Dell Data Domain backup repository, Veeam Backup & Replication will offer you to switch to optimized job settings and use the 4 MB size of data block for workload data processing (the Storage optimization setting). It is recommended that you use optimized job settings. Large data blocks produce a smaller metadata table that requires less memory and CPU resources to process. For more information on storage optimization, see Data Compression and Deduplication.
- Dell Data Domain does not support the reverse incremental backup method.
- You cannot use Dell Data Domain backup repositories as sources or targets for file copy jobs.
- The length of forward incremental and forever forward incremental backup chains (chains that contain one full backup and a set of subsequent incremental backups) cannot be greater than 120 restore points. To overcome this limitation, schedule full backups (active or synthetic) to split the backup chain into shorter series. For example, to perform backups at 15-minute intervals 24 hours a day, you must schedule synthetic fulls every day. In this scenario, intervals immediately after midnight may be skipped due to duration of synthetic processing. For more information, see How Synthetic Full Backup Works.
- If you connect to an Dell Data Domain backup repository over Fibre Channel, you must explicitly define a gateway server to communicate with Dell Data Domain. As a gateway server, you must use a Microsoft Windows server that is added to the backup infrastructure and has access to the Dell Data Domain backup repository over Fibre Channel.
- During backup repository rescan, Veeam Backup & Replication detects if the hard stream limit is set for a storage unit, and displays this information in backup repository rescan statistics. If the hard stream limit is exceeded when Veeam Backup & Replication runs tasks against the backup repository, Veeam Backup & Replication will fail to create new I/O streams.