Linked by Thom Holwerda on Mon 2nd Nov 2009 23:20 UTC
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."
Thread beginning with comment 392787
To view parent comment, click here.
To read all comments associated with this story, please click here.
To view parent comment, click here.
To read all comments associated with this story, please click here.
Recent Original Stories
Recent Comments
Headlines
Random Comments
Random Stories
Random OS Link
Member since:
2007-03-26
Sorry, you're right.
I thought the article stated that you could choose which of the 3 levels of dedup you wanted ZFS to perform, but it wasn't. It was just detailing the theory of dedup and the levels around.