Linked by Thom Holwerda on Mon 2nd Nov 2009 23:20 UTC
Sun Solaris, OpenSolaris ZFS has received built-in deduplication. "Deduplication is the process of eliminating duplicate copies of data. Dedup is generally either file-level, block-level, or byte-level. Chunks of data - files, blocks, or byte ranges - are checksummed using some hash function that uniquely identifies data with very high probability. Chunks of data are remembered in a table of some sort that maps the data's checksum to its storage location and reference count. When you store another copy of existing data, instead of allocating new space on disk, the dedup code just increments the reference count on the existing data. When data is highly replicated, which is typical of backup servers, virtual machine images, and source code repositories, deduplication can reduce space consumption not just by percentages, but by multiples."
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RE[2]: I skimmed the article...
by Tuxie on Tue 3rd Nov 2009 14:15 UTC in reply to "RE: I skimmed the article..."
Tuxie
Member since:
2009-04-22

HTPC / media servers: if you have lot's of DVD rips of TV shows, then you could save several hundred MBs with the intro/outro credits being duduped alone.

Err, no. There is no way the intro/outro scenes are going to be byte-by-byte-identical in the encoded data for different episodes even if they look identical to the eye. Even if nothing else is, the timestamp metadata for each frame is going to differ.

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