Data compression and deduplication – veeam backup guide for hyper-v

Veeam Backup & Replication provides mechanisms of data compression and deduplication. Sql server 2008 express Data compression and deduplication let you decrease traffic going over the network and disk space required for storing backup files and VM replicas.

Data compression decreases the size of created backups but affects duration of the backup procedure. As sql server Veeam Backup & Replication allows you to select one of the following compression levels:

• None compression level is recommended if you use plan to store backup files and VM replica files on storage devices that support hardware compression and deduplication.


• Dedupe-friendly is an optimized compression level for very low CPU usage. Database sql server 2008 You can select this compression level if you want to decrease the load on the backup proxy.

• Extreme compression provides the smallest size of the backup file but reduces the backup performance. When in sql server We recommend that you run backup proxies on computers with modern multi-core CPUs (6 cores recommended) if you intend to use the extreme compression level.

Data deduplication decreases the size of backup files. Ms sql server download You can enable data deduplication if you add to backup or replication jobs several VMs that have a great amount of free space on their logical disks or VMs that have similar data blocks — for example, VMs that were created from the same template. Sql server 2008 r2 express edition With data deduplication enabled, Veeam Backup & Replication does not store to the resulting backup file identical data blocks and space that has been pre-allocated but not used.

• The source-side Veeam Data Mover deduplicates VM data at the level of VM disks. Sql server and or Before the source Veeam Data Mover starts processing a VM disk, it obtains digests for the previous restore point in the backup chain from the target-side Veeam Data Mover. Sql server 2008 wiki The source-side Veeam Data Mover consolidates this information with CBT information from the hypervisor and filters VM disk data based on it. Sql server release history If some data block exists in the previous restore point for this VM, the source-side Veeam Data Mover does not transport this data block to the target. Sql 2012 server In addition to it, in case of dynamically expanded disks the source-side Veeam Data Mover skips unallocated space.

• The target-side Veeam Data Mover deduplicates VM data at the level of the backup file. Sql server trigger It processes data for all VM disks of all VMs in the job. Sql server security The target-side Veeam Data Mover uses digests to detect identical data blocks in transported data, and stores only unique data blocks to the resulting backup file.

Depending on the type of storage you select as a backup target, Veeam Backup & Replication uses data blocks of different size to process VMs, which optimizes the size of a backup file and job performance. Sql 2000 server You can choose one of the following storage optimization options:

• The Local target (16 TB + backup files) option is recommended for backup jobs that can produce very large full backup files — larger than 16 TB. Sql server 2000 enterprise manager With this option selected, Veeam Backup & Replication uses data block size of 4096 KB.

If you select to use data blocks of small size to dedupicate a large backup file, the backup file will be cut into a great number of data blocks. What is sql server database As a result, Veeam Backup & Replication will produce a very large deduplication metadata table which can potentially overgrow memory and CPU resources of your backup repository. Sql server 2008 versions For backup files over 16 TB, it is recommended to choose the Local target (16 TB + backup size) option. Sql server express 2014 With this option selected, Veeam Backup & Replication will use data blocks of 4 MB. Sql server 2012 advanced services Large data blocks produce a smaller metadata table that requires less memory and CPU resources to process. Sql server 2012 express with tools Note, however, that this storage optimization option will provide the lowest deduplication ratio and the largest size of incremental backup files.

If you upgrade to Veeam Backup & Replication 9.0 from the previous product version, this option will be displayed as Local target (legacy 8MB block size) in the list and will still use blocks size of 8 MB. Sql server express edition 2012 It is recommended that you switch to an option that uses a smaller block size and create an active full backup to apply the new setting.

• The Local target option is recommended for backup to SAN, DAS or local storage. Sql server express commercial use With this option selected, Veeam Backup & Replication uses data block size of 1024 KB.

The SAN identifies larger blocks of data and therefore can process large amounts of data at a time. Different versions of sql server This option provides the fastest backup job performance but reduces the deduplication ratio, because with larger data blocks it is less likely to find identical blocks.

• The LAN target option is recommended for backup to NAS and onsite backup. Sql server editions With this option selected, Veeam Backup & Replication uses data block size of 512 KB. Sql server express edition 2008 This option provides a better deduplication ratio and reduces the size of a backup file because of reduced data block sizes.

• The WAN target option is recommended if you are planning to use WAN for offsite backup. Sql server express edition 2008 r2 With this option selected, Veeam Backup & Replication uses data block size of 256 KB. Sql server 2000 developer edition This results in the maximum deduplication ratio and the smallest size of backup files, allowing you to reduce the amount of traffic over WAN.

You can change data compression settings for existing backup jobs. For sql server New settings will not have any effect on previously created backup files in the backup chain. Sql database server They will be applied to new backup files created after the settings were changed.

Compression settings are changed on the fly. Sql server compact edition You do not need to create a new full backup to use new settings — Veeam Backup & Replication will automatically apply the new compression level to newly created backup files.

However, if you use the reverse incremental backup method, the newly created backup files will contain a mixture of data blocks compressed at different levels. Sql server migration For example, you have a backup job that uses the reverse incremental backup method and the Optimal level of compression. Sql server express server name After several job sessions, you change the compression level to High. Why sql server In the reverse incremental backup chains, the full backup file is rebuilt with every job session to include new data blocks. Sql server 2008 As a result, the full backup file will contain a mixture of data blocks: data blocks compressed at the Optimal level and data blocks compressed at the High level.

If you want the newly created backup file to contain data blocks compressed at one level, you can create an active full backup. Ms sql server enterprise Veeam Backup & Replication will retrieve data for the whole VM image from the production infrastructure and compress it at the new compression level. And sql server All subsequent backup files in the backup chain will also use the new compression level.

You can change data deduplication settings for existing backup jobs. Sql server 2008 developer edition New settings will not have any effect on previously created backup files in the backup chain. Sql server last version They will be applied to new backup files created after the settings were changed.

To apply new deduplication settings in backup jobs, you must create an active full backup after you change deduplication settings. Sql server latest Veeam Backup & Replication will use the new block size for the active full backup and subsequent backup files in the backup chain.

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