From e1f8da0db3d73421c6bfc429a93672d32b5875da Mon Sep 17 00:00:00 2001
From: FQHSLycopene <110231817+FQHSLycopene@users.noreply.github.com>
Date: Tue, 29 Jul 2025 03:24:56 +0800
Subject: [PATCH] fix: consider EC shard count in volume.balance capacity
 calculation (#7034)

* fix: consider EC shard count in volume.balance capacity calculation

* update the implementation of capacityByMaxVolumeCount to include the EC shard usage
---
 weed/shell/command_volume_balance.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/weed/shell/command_volume_balance.go b/weed/shell/command_volume_balance.go
index ac7dab3d9..b3c76a172 100644
--- a/weed/shell/command_volume_balance.go
+++ b/weed/shell/command_volume_balance.go
@@ -225,7 +225,11 @@ func capacityByMaxVolumeCount(diskType types.DiskType) CapacityFunc {
 		if !found {
 			return 0
 		}
-		return float64(diskInfo.MaxVolumeCount)
+		var ecShardCount int
+		for _, ecShardInfo := range diskInfo.EcShardInfos {
+			ecShardCount += erasure_coding.ShardBits(ecShardInfo.EcIndexBits).ShardIdCount()
+		}
+		return float64(diskInfo.MaxVolumeCount) - float64(ecShardCount)/erasure_coding.DataShardsCount
 	}
 }