根据dump的结果，在word里面画了一个非常简单的示意图，每个数据文件最前面的8个块，是LMT用于管理extent分配的。
更详细的文档可以参考itpub电子杂志internal专刊中piner关于LMT和ASSM的文章。
数据文件（ LMT+ASSM ）（每格为 1 个 block ， block size 为 8k ）
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FIRST LEVEL BITMAP BLOCK
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SECOND LEVEL BITMAP BLOCK
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PAGETABLE SEGMENT HEADER
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
FIRST LEVEL BITMAP BLOCK
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SECOND LEVEL BITMAP BLOCK
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PAGETABLE SEGMENT HEADER
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
FIRST LEVEL BITMAP BLOCK
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SECOND LEVEL BITMAP BLOCK
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PAGETABLE SEGMENT HEADER
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
Data Block
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
FIRST LEVEL BITMAP BLOCK
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
数据文件（ LMT ）（每格为 1 个 block ， block size 为 8k ）
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DATA SEGMENT HEADER - UNLIMITED
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
DATA SEGMENT HEADER - UNLIMITED
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
DATA SEGMENT HEADER - UNLIMITED
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
Data Block
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
Data Block
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block
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Data Block