From 139e5a3e29d009d6af4e2c5f1e347d5a5acc2791 Mon Sep 17 00:00:00 2001
From: brinkcoder <Robert.Externbrink@ruhr-uni-bochum.de>
Date: Fri, 7 Mar 2025 15:30:56 +0100
Subject: [PATCH] fix: first values are now 0 for _diff metrics

---
 collectors/iostatMetric.go | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/collectors/iostatMetric.go b/collectors/iostatMetric.go
index e78b252..eaa0e48 100644
--- a/collectors/iostatMetric.go
+++ b/collectors/iostatMetric.go
@@ -154,8 +154,15 @@ func (m *IOstatCollector) Init(config json.RawMessage) error {
 			continue
 		}
 		values := make(map[string]int64)
-		for mname := range m.matches {
-			values[mname] = 0
+		for mname, idx := range m.matches {
+			if idx < len(linefields) {
+				x, err := strconv.ParseInt(linefields[idx], 0, 64)
+				if err == nil {
+					values[mname] = x
+				}
+			} else {
+				values[mname] = 0
+			}
 		}
 		m.devices[device] = IOstatCollectorEntry{
 			tags: map[string]string{