16 lines
822 B
Plaintext
16 lines
822 B
Plaintext
zbackup is a globally-deduplicating backup tool, based on the ideas found in
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rsync.
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Feed a large .tar into it, and it will store duplicate regions of it only
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once, then compress and optionally encrypt the result. Feed another .tar file,
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and it will also re-use any data found in any previous backups.
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This way only new changes are stored, and as long as the files are not very
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different, the amount of storage required is very low. Any of the backup files
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stored previously can be read back in full at any time.
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This is achieved by sliding a window with a rolling hash over the input at a
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byte granularity and checking whether the block in focus was ever met already.
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If a rolling hash matches, an additional full cryptographic hash is calculated
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to ensure the block is indeed the same. The deduplication happens then.
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