Difference between revisions of "Ploop/format"
< Ploop
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A ploop image file format is pretty simple. | A ploop image file format is pretty simple. | ||
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* Image consists of cluster blocks (default cluster block size is 1 MB). | * Image consists of cluster blocks (default cluster block size is 1 MB). | ||
* First there are some cluster blocks with BAT (Block Allocation Table), then there are some cluster blocks with data. | * First there are some cluster blocks with BAT (Block Allocation Table), then there are some cluster blocks with data. | ||
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* If a slot N contains value M, then a request to a cluster-block N of a /dev/ploopXXX device is redirected to a cluster-block M in an image file. N is counted from 0, while M is counted from 1 (0 means block is not yet allocated). | * If a slot N contains value M, then a request to a cluster-block N of a /dev/ploopXXX device is redirected to a cluster-block M in an image file. N is counted from 0, while M is counted from 1 (0 means block is not yet allocated). | ||
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For the rest of the story, see sources. | For the rest of the story, see sources. | ||
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[[Category: Storage]] | [[Category: Storage]] | ||
Latest revision as of 22:26, 25 December 2015
<translate> A ploop image file format is pretty simple.
- Image consists of cluster blocks (default cluster block size is 1 MB).
- First there are some cluster blocks with BAT (Block Allocation Table), then there are some cluster blocks with data.
- First 64 bytes of the first cluster block is a header, described in ploop1_image.h
- The rest of BAT is just an array of 4 byte slots.
- If a slot N contains value M, then a request to a cluster-block N of a /dev/ploopXXX device is redirected to a cluster-block M in an image file. N is counted from 0, while M is counted from 1 (0 means block is not yet allocated).
For the rest of the story, see sources. </translate>
