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Backing up in trees with Obnam 1.0Backing up in trees with Obnam 1.0Posted Jun 7, 2012 22:29 UTC (Thu) by oever (subscriber, #987)In reply to: Backing up in trees with Obnam 1.0 by rbrito Parent article: Backing up in trees with Obnam 1.0
First off: I have not tested bup myself on a significant amount of data; so far I'm content with reading parts of the code and the documentation and thinking about scenarios for using it.
Ocman seems to do de-duplication on fixed blocks, not variable blocks as one would get with a rolling checksum. You can configure the block size, but i think the boundary positions are simply multiples of the block size.
When using a rolling checksum, one moves a window over the data and when the checksum value falls in a particular range, the block ends. This means that the blocks have different sizes. The size depends on the content. By choosing the range for the checksum values that trigger a split, one can influence the average blocks in the backup.
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Backing up in trees with Obnam 1.0 Posted Jun 8, 2012 10:27 UTC (Fri) by rbrito (subscriber, #66188) [Link]
Please, excuse my ignorance here, but you have consistently used the name ocman.
Is ocman a typo for obnam?
I don't find any hits related to backups doing some searches with ocman as a keyword (e.g. https://duckduckgo.com/?q=ocman+backup).
Backing up in trees with Obnam 1.0 Posted Jun 8, 2012 12:36 UTC (Fri) by oever (subscriber, #987) [Link]
It was an error, I meant obnam, not ocman.
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