diff --git a/pkg/internal/mysqlcluster/defaults.go b/pkg/internal/mysqlcluster/defaults.go
index 7b4f48ecd..d7aa0803c 100644
--- a/pkg/internal/mysqlcluster/defaults.go
+++ b/pkg/internal/mysqlcluster/defaults.go
@@ -18,10 +18,13 @@ package mysqlcluster
 
 import (
 	"fmt"
+
 	core "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/intstr"
 
+	api "github.com/presslabs/mysql-operator/pkg/apis/mysql/v1alpha1"
 	"github.com/presslabs/mysql-operator/pkg/options"
 )
 
@@ -34,7 +37,6 @@ const (
 )
 
 // SetDefaults set defaults from options
-// nolint: gocyclo
 func (cluster *MysqlCluster) SetDefaults(opt *options.Options) {
 	// set default image pull policy
 	if len(cluster.Spec.PodSpec.ImagePullPolicy) == 0 {
@@ -66,49 +68,43 @@ func (cluster *MysqlCluster) SetDefaults(opt *options.Options) {
 	// https://www.percona.com/blog/2018/03/26/mysql-8-0-innodb_dedicated_server-variable-optimizes-innodb/
 
 	// set innodb-buffer-pool-size if not set
-	if _, ok := cluster.Spec.MysqlConf["innodb-buffer-pool-size"]; !ok {
-		if mem := cluster.Spec.PodSpec.Resources.Requests.Memory(); mem != nil {
-			var bufferSize int64
-			if mem.Value() < gb {
-				// RAM < 1G => buffer size set to 128M
-				bufferSize = 128 * mb
-			} else if mem.Value() <= 4*gb {
-				// RAM <= 4gb => buffer size set to RAM * 0.5
-				bufferSize = int64(float64(mem.Value()) * 0.5)
-			} else {
-				// RAM > 4gb => buffer size set to RAM * 0.75
-				bufferSize = int64(float64(mem.Value()) * 0.75)
-			}
+	if mem := cluster.Spec.PodSpec.Resources.Requests.Memory(); mem != nil {
+		bufferSize := humanizeSize(computeInnodbBufferPoolSize(mem))
+		setConfigIfNotSet(cluster.Spec.MysqlConf, "innodb-buffer-pool-size", bufferSize)
+	}
 
-			cluster.Spec.MysqlConf["innodb-buffer-pool-size"] = humanizeSize(bufferSize)
-		}
+	if mem := cluster.Spec.PodSpec.Resources.Requests.Memory(); mem != nil {
+		logFileSize := humanizeSize(computeInnodbLogFileSize(mem))
+		setConfigIfNotSet(cluster.Spec.MysqlConf, "innodb-log-file-size", logFileSize)
 	}
 
-	if _, ok := cluster.Spec.MysqlConf["innodb-log-file-size"]; !ok {
-		if mem := cluster.Spec.PodSpec.Resources.Requests.Memory(); mem != nil {
-			var logFileSize int64
-			if mem.Value() < gb {
-				// RAM < 1G
-				logFileSize = 48 * mb
-			} else if mem.Value() <= 4*gb {
-				// RAM <= 4gb
-				logFileSize = 128 * mb
-			} else if mem.Value() <= 8*gb {
-				// RAM <= 8gb
-				logFileSize = 512 * mb
-			} else if mem.Value() <= 16*gb {
-				// RAM <= 16gb
-				logFileSize = 1 * gb
-			} else {
-				// RAM > 16gb
-				logFileSize = 2 * gb
+	if pvc := cluster.Spec.VolumeSpec.PersistentVolumeClaim; pvc != nil {
+		if space := getStorage(pvc.Resources.Requests); space != nil {
+			binlogSpaceLimit := 50 / 100 * space.Value()
+			maxBinlogSize := min(25/100*binlogSpaceLimit, 1*gb)
+			if space.Value() < 2*gb {
+				binlogSpaceLimit = 33 / 100 * space.Value()
+				maxBinlogSize = min(33/100*binlogSpaceLimit, 1*gb)
 			}
-
-			cluster.Spec.MysqlConf["innodb-log-file-size"] = humanizeSize(logFileSize)
+			setConfigIfNotSet(cluster.Spec.MysqlConf, "max-binlog-size", humanizeSize(maxBinlogSize))
+			setConfigIfNotSet(cluster.Spec.MysqlConf, "binlog-space-limit", humanizeSize(binlogSpaceLimit))
 		}
 	}
 }
 
+func setConfigIfNotSet(conf api.MysqlConf, option string, value intstr.IntOrString) {
+	if _, ok := conf[option]; !ok {
+		conf[option] = value
+	}
+}
+
+func getStorage(rl core.ResourceList) *resource.Quantity {
+	if val, ok := rl[core.ResourceStorage]; ok {
+		return &val
+	}
+	return nil
+}
+
 func humanizeSize(value int64) intstr.IntOrString {
 	var unit string
 
@@ -122,3 +118,51 @@ func humanizeSize(value int64) intstr.IntOrString {
 
 	return intstr.FromString(fmt.Sprintf("%d%s", value, unit))
 }
+
+// computeInnodbLogFileSize returns a computed value, to configure MySQL, based on requested memory.
+func computeInnodbLogFileSize(mem *resource.Quantity) int64 {
+	var logFileSize int64
+	if mem.Value() < gb {
+		// RAM < 1G
+		logFileSize = 48 * mb
+	} else if mem.Value() <= 4*gb {
+		// RAM <= 4gb
+		logFileSize = 128 * mb
+	} else if mem.Value() <= 8*gb {
+		// RAM <= 8gb
+		logFileSize = 512 * mb
+	} else if mem.Value() <= 16*gb {
+		// RAM <= 16gb
+		logFileSize = 1 * gb
+	} else {
+		// RAM > 16gb
+		logFileSize = 2 * gb
+	}
+
+	return logFileSize
+}
+
+// computeInnodbBufferPoolSize returns a computed value, to configure MySQL, based on requested
+// memory.
+func computeInnodbBufferPoolSize(mem *resource.Quantity) int64 {
+	var bufferSize int64
+	if mem.Value() < gb {
+		// RAM < 1G => buffer size set to 128M
+		bufferSize = 128 * mb
+	} else if mem.Value() <= 4*gb {
+		// RAM <= 4gb => buffer size set to RAM * 0.5
+		bufferSize = int64(float64(mem.Value()) * 0.5)
+	} else {
+		// RAM > 4gb => buffer size set to RAM * 0.75
+		bufferSize = int64(float64(mem.Value()) * 0.75)
+	}
+
+	return bufferSize
+}
+
+func min(a, b int64) int64 {
+	if a <= b {
+		return a
+	}
+	return b
+}