From 10f200f62546699131321e6324979697a57ac517 Mon Sep 17 00:00:00 2001 From: Chris Lu Date: Wed, 26 Jun 2019 22:25:04 -0700 Subject: [PATCH] Updated Erasure Coding for warm storage (markdown) --- Erasure-Coding-for-warm-storage.md | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/Erasure-Coding-for-warm-storage.md b/Erasure-Coding-for-warm-storage.md index 3b15c10..b19c815 100644 --- a/Erasure-Coding-for-warm-storage.md +++ b/Erasure-Coding-for-warm-storage.md @@ -20,6 +20,11 @@ The downside: * Only deletion is supported. Update is not supported. * Compaction is WIP. This would require transmitting whole volume data. +Side Note: +* The 10+4 can be easily adjusted via `DataShardsCount` and `ParityShardsCount` in +https://github.com/chrislusf/seaweedfs/blob/master/weed/storage/erasure_coding/ec_encoder.go#L17 +* If you are considering these enterprise-level customizations, please consider donate to SeaweedFS first. + ## 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.