"Deduplication strips out redundant data from files at the sub-file level. HP is claiming it can provide a reduction in backup file size of up to 50:1......."

Is this the same as lossless data compression (ZIP etc) or is it something new/extra/special?

"HP states that the data deduplication technology for the VLS and D2D enables customers to automate and remotely manage the systems with low-bandwidth replication. This provides data center managers the ability to back up data remotely without manual intervention, thereby reducing staffing costs."

Is this the same as saying 'It's hard drive storage so there's no need for on-site staff to take care of loading tapes." ? If so, why didn't they just say that?

LZH and friends are a family of "data deduplication algorithms"; huffman coding and all that jazz are based on well established principles of information theory, which is based around "de-duplicating" repeated data.

So, HP have a tape compression system. What's new about that exactly, apart from the name?

I have file collections that are 10 times smaller as tar.gz than as .zip

The difference is that zip compresses each file then starts fresh on the next one while tar creates a huge file with all of the contents of the sub files and then condenses the entropy in that huge file, which lets it take advantage of repeats between files and even in the file headers under tar.

No, wait... it's not in the comments section, it's the start of the article. Ow!