Single instance storage

Enterprise Vault can use single instance storage to optimize archive storage space. Enterprise Vault's single instance storage mechanism archives a single instance of parts of an item that are suitable for sharing, such as large message attachments. Enterprise Vault can share the single instance storage parts (SIS parts) within a vault store, or across two or more vault stores within a vault store group. A vault store group forms an outer boundary for sharing.

Enterprise Vault single instance storage is not performed when items are stored to partitions that are hosted on EMC Centera devices. You can configure a partition for an EMC Centera device to use theCentera's device-level sharing mechanism, if required. Enterprise Vault then stores the shareable parts of a saveset as separate data blobs, so that the Centera device is able to share them.

If you use Enterprise Vault's single instance storage mechanism, you need to create a sharing regime that meets your organization's data sharing requirements and which is appropriate for your network connection speeds. Consider what sort of sharing regime you require before you start archiving. Enterprise Vault cannot share items retrospectively. Also there are limits to what you can change after Enterprise Vault has started sharing items.

For more information about setting up single instance storage, see "Setting up Storage" in Installing and Configuring.