4 4 3:Configuring Si3 Deduplication Store

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Any form of reproduction of the contents or parts of this manual is allowed only with the express written permission from SEP AG. When compiling and designing user documentation SEP AG uses great diligence and attempts to deliver accurate and correct information. However, SEP AG cannot issue a guarantee for the contents of this manual.

Icon archived docs.png This is not the latest version of SEP sesam documentation and, as such, does not provide information on features introduced in the latest release. For more information on SEP sesam releases, see SEP sesam Release Versions. For the latest documentation, check SEP sesam Documentation.


SEP sesam provides a target-based (Si3T) and source-based deduplication (Si3S). For details on deduplication concept and recommendations, see Deduplication.

Both, Si3T and Si3S require a configured Si3 deduplication store. Only one Si3 deduplication store can be configured on a server. A valid licence is required for each Si3 deduplication store. Note that you can also configure an Si3 deduplication store by using a command line. For details, see Configuring and Administering Si3 Deduplication Store by using CLI.

You can download SEP Tachometer to analyse the structure of your data and calculate potential savings with SEP sesam Si3 deduplication. Check SEP Tachometer.


For the minimum Si3 hardware requirements that apply to SEP sesam Si3 deduplication server, see Hardware requirements. Keep in mind that these requirements represent the demand for deduplication only. In addition, the amount of memory for the operating system and other services should be taken into account.

In addition, the following prerequisites must be met to configure an Si3 deduplication store.

Additional RAM / CPU requirements

  • For details on the required Java version, see Java Compatibility Matrix. Si3 is not mandatory, therefore there is no dependency rule in the RPM/DEB packages for it.
  • When estimating the maximum size for a deduplication store, you have to ensure that there is enough space available for dedup trash or the deduplication store will run out of space. You should calculate the required disk space based on the representative sample of your full backup and add the amount of extra space equal to approx. 50% of the representative full backup.

Disk attachment and protocols

Si3 supports any kind of direct-attached disk storage, such as serial attached SCSI (SAS), Serial ATA (SATA), and Fibre Channel (FC)/LUN. Si3 is NOT supported for CIFS and NFS network protocols.


To avoid issues arising from combination of too large Si3 deduplication stores and inefficient hardware, the maximum initial Si3 deduplication store size is restricted to 40 TB since Tigon V2 ( This restriction is valid when creating a new Si3 deduplication store in GUI. Note that customers with special requirements for larger Si3 deduplication store should contact SEP support to be able to increase the value up to an optimum size for their specific environments.

Required additional amount of RAM and CPU cores

The following tables show the required additional amount of RAM and CPU cores for one Si3 data store. The TB value is the capacity of the Si3 data store.

Information sign.png Note
It is not recommended to run Si3 deduplication (SEP sesam Server or RDS) on a virtual machine. If this is the case, like evaluation or test, consider to limit the capacity of Si3 data store to 100 GB thus ensuring normal VM operation. Have in mind that deduplication consumes a lot of server resources for reading, processing, and writing deduplicated data, therefore you should be aware of running Si3 on a VM deployment limitation.
Si3 data store capacity (check initial size restriction) RAM
<20 TB 16 GiB
20-40 TB 32 GiB

To find out how much RAM is required by Si3 at which capacity, enter the command sm_dedup_interface propose jvmconfig <Si3-CAPACITY> at an admin command line (you must set sesam profile to run the command). The MaxDirectMemorySize output is the required RAM value.

The following table shows the amount of CPU cores required for one Si3 data store. The TB value is the amount of backed up data (before deduplication)!

Backed up data (before dedup) CPU cores
10 TB 4
20 TB 4
40 TB 8
Information sign.png Note
Keep in mind that the stated requirements represent the demand for deduplication only. In addition to these requirements, the amount of memory for the operating system and other services should be taken into account.


The SEP sesam data store is a disk based storage that enables save sets (backed up data) to be backed up directly to the configured storage locations. SEP Si3 target deduplication is easily configured and ready to use by selecting Si3 deduplication data store type.

  1. In the Main selection -> Components, click Data stores to display the data store contents frame.
  2. From the Data stores menu, select New data store. A New data store dialog appears.
  3. GUI new data store.png

  4. Under the Data store properties in the Name field, enter a meaningful name for the data store.
  5. From the Store type drop-down list, select SEP Si3 deduplication store. Skip the Messages section, which is used by SEP sesam to display the last executed action.
  6. GUI new data store 1.png

  7. Make sure that the option Create drive for data store is checked under the Drive parameter properties. The predefined value for the drive is automatically added to the Drive number field.
  8. From the Device server drop-down list, select the device server for your data store.
  9. In the Path field, enter the location for your data store or use the Browse button to select the relevant folder. Check the relevant folder and click OK.
    When using the Browse button to select the folder, the New data store information window appears with predefined recommended values for your Si3 deduplication store size. Click OK to confirm the selected location and the recommended size values. You can modify your data store size later under the Size properties (see step 10).
  10. GUI new data store information.png

  11. Under the Drive group properties, select Create new drive group and enter the name for your Si3 deduplication store dedicated group.
  12. The predefined number of channels is already displayed in the Max. channels drop-down list. The number of available channels depends on your SEP sesam Server package. The standard license supports 5 concurrent streams, enabling 5 backup processes to run simultaneously. For details on licensing, see SEP sesam license.
  13. Under the Size properties, specify or modify the following:
    • Capacity: Specify the size (in GB) of the partition for backups.
    • High watermark: Specify the value (in GB) for the high watermark (HWM). The HWM defines the upper value for used disk space. When this value is reached, a purge process is triggered for all EOL-free (End-of-lifetime) save sets, thus freeing up the capacity of the data store.
    • Low watermark: Specify the value (in GB) for the low watermark (LWM). The LWM defines how much storage space is available in the data store for files with an expired EOL. If the LWM is set to 0, all EOL-free save sets are removed from the data store. The oldest save sets are always deleted first. The LWM for the deduplication store is set to 0 by default and cannot be edited.

    The Disk space usage properties are used by SEP sesam to report the following:

    • Used: Total used space (in GB) on the partition.
    • Total: Maximum available space (in GB) on the partition as reported by the operating system.
    • Free: Available disk space (in GB) for SEP sesam.
    • Deduplication rate: deduplication occurs once the backup process has started. SEP sesam analyses blocks of data and determines whether the data is unique or has already been copied to the Si3 data store. Only single instances of unique data are sent to the data store and replace each deduplicated file with a stub file. The deduplication rate is higher when there are copy and full backups and when there is a larger amount of data. The deduplication ratio is depicted as ratio:1.

As of v. 4.4.3 Tigon, it is possible to encrypt Si3 deduplication store. For details, see Encrypting Si3 Deduplication Store.

Also introduced in Tigon is initial seed that allows you to seed the Si3 deduplication store for the purpose of replication. For details, see Seeding Si3 Deduplication Store.

What is next?

After configuring the Si3 deduplication store, configure the media pools first then set up your backup strategy.

See also

Configuring and Administering Si3 Deduplication Store by using CLIEncrypting Si3 Deduplication StoreConfiguring Source-side DeduplicationReplicationSeeding Si3 Deduplication StoreSEP TachometerList of Licenses