{{Note|After each (but the last) dump tasks continue running and thus can modify filesystem. CRIU doesn't snapshot filesystem and assumes, that proper filesystem state for restore is provided by user}}
{{Note|After each (but the last) dump tasks continue running and thus can modify filesystem. CRIU doesn't snapshot filesystem and assumes, that proper filesystem state for restore is provided by user}}
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== Data deduplication ==
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After creation of such stack of images some data would get duplication in dumps. If you don't want to keep duplicates there's an ability to punch duplicate data from non-top images. There are two options for this.
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; Deduplication action
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: The <code>crui dedup</code> command would open the image directory and punch holes in the ''parent'' images in needed places
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; Automatic deduplication while dumping
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: The <code>--auto-dedup</code> option would cause every write to images with process' pages to go an punch holes in respective parent images.
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The latter option appies to both <code>dump</code> and <code>page-server</code> actions and thus is extremely useful in [[disk-less migration]] scenario.