From f2c84f15aa265437cc719b7814ecdd78f013ac85 Mon Sep 17 00:00:00 2001 From: Chris Lu Date: Tue, 11 Jun 2019 00:43:36 -0700 Subject: [PATCH] Updated Erasure Coding for warm storage (markdown) --- Erasure-Coding-for-warm-storage.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Erasure-Coding-for-warm-storage.md b/Erasure-Coding-for-warm-storage.md index 20e3b85..0061c79 100644 --- a/Erasure-Coding-for-warm-storage.md +++ b/Erasure-Coding-for-warm-storage.md @@ -15,7 +15,7 @@ However, data can become warm or cold after a period of time. They are accessed ## Architecture SeaweedFS implemented 10.4 Reed-Soloman Erasure Coding (EC). The large volumes are split into chunks of 1GB, and every 10 data chunks are also encoded into 4 parity chunks. So a 30 GB data volume will be encoded into 14 EC shards, each shard is of size 3 GB and has 3 EC blocks. -Since the data is split into 1GB chunks, usually one small file is contained in shard, or possibly two shards in edge cases. So most reads still only cost O(1) disk read. +Since the data is split into 1GB chunks, usually one small file is contained in one shard, or possibly two shards in edge cases. So most reads still only cost O(1) disk read. For smaller volumes less than 10GB, and for edge cases, the volume is split into smaller 1MB chunks.