Is EMC with data domain deduplication compatible with LiteSpeed?
Per the LiteSpeed Product Manager, LiteSpeed is certified on DataDomain and ExaGrid and works well with all deduplication appliances.
The recommended solution for smallest backups is to use Fast Compression at compression level 0, but any type of LiteSpeed backup will work whether compression is used or not or the customer prefers to perform nightly, full backups.
For documentation from EMC on this topic, see the attachment to this Solution.
Also, Quest's NetVaultBackUp works well with Data Domains.