1000-introduction.html

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   7     Bitmaps and NBD: Building Blocks of Change Block Tracking
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  10   <p class="author">
  11     Eric Blake <small>(eblake @ redhat.com)</small> <br>
  12     <small>15:30 Friday October 30th, 2020</small>
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  15   <p class="abstract">
  16     Incremental backups depend on change block tracking: if you know
  17     which portions of a disk image have changed, you can optimize your
  18     backups to visit just those portions.  This talk explores how qemu
  19     uses <b>qcow2 dirty bitmaps</b> to track changed blocks, and how
  20     the <b>Network Block Device (NBD) protocol</b> can then expose
  21     that for use in backup scenarios.
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  23 </div>