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+This erasure coding implementation took some ideas from [f4: Facebook’s Warm BLOB Storage System](https://www.usenix.org/system/files/conference/osdi14/osdi14-paper-muralidhar.pdf).
+
 Usually data is hot when it is fresh, and are accessed very often. SeaweedFS normal volumes tries hard to minimize the disk operations, but it comes with a cost of loading indexes in memory. 
 
 However, data can become warm or cold after a period of time. They are accessed much less often. The high cost of memory is not cost-efficient for warm storage. To store them more efficiently, you can "seal" the data and enable erasure coding (EC).