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Memory dumps

65 bytes added, 06:10, 31 August 2016
Stacked images: rephrasing
== Stacked images ==
When you do [[incremental dumps]] there appear the are performed, for every iteration a <code>parent</code> symlink is created, and images with pages become dependant dependent on each othertheir respective parent(s).
There appears the 3rd field in the pagemap, called <code>in_parent</code>. When It is a boolean flag, when set this boolean value , means, that the respective data for the given pagemap should be found in the is available from a parent imagesimage. While searching for data in parent , the same algorithm is used -- first the pagemap is resolved, then the data is found in pages. For parent images, the data (either complete or partial) can also be found in ''its'' parent images.
RespectivelyNaturally, the bottom image (the one with no parent link) should must have no <code>in_parent </code> bits at allset.
=== Example ===
Let's take another example, consider Consider we have a pagemap from the previous example with one <code>in_parent </code> bitset for one entry:
In this case , the pages image would be only 32k in size, since the first 4 pages should are to be found in the parent. Thus the parent pagemap image should container one ore or more pagemaps that cover covering the <code>0x1000000 ... 0x1004000</code> area, for example , like this
This, in turn, would mean means that the first 2 pages from this range are in available from the parent's pages image file , and the last 2 should be looked up deeper -- , i.e. in the grand-parent pagemaps.
== Deduplication ==

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