From 2e43cd9d62530a32ab661ec1a219f3043eac63c8 Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@victoriametrics.com>
Date: Wed, 1 Dec 2021 10:56:21 +0200
Subject: [PATCH] lib/storage: do not take into account
 -storage.minFreeDiskSpaceBytes during background merges

---
 lib/storage/partition.go | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/lib/storage/partition.go b/lib/storage/partition.go
index 22c4b0702b..dbe5920e11 100644
--- a/lib/storage/partition.go
+++ b/lib/storage/partition.go
@@ -978,10 +978,9 @@ func SetFinalMergeDelay(delay time.Duration) {
 
 func getMaxOutBytes(path string, workersCount int) uint64 {
 	n := fs.MustGetFreeSpace(path)
-	if n < freeDiskSpaceLimitBytes {
-		return 0
-	}
-	n -= freeDiskSpaceLimitBytes
+	// Do not substract freeDiskSpaceLimitBytes from n before calculating the maxOutBytes,
+	// since this will result in sub-optimal merges - e.g. many small parts will be left unmerged.
+
 	// Divide free space by the max number concurrent merges.
 	maxOutBytes := n / uint64(workersCount)
 	if maxOutBytes > maxBigPartSize {