use sparse rw layer by default

WaberZhuang · WaberZhuang · commit ace1bb444e3f · 2026-01-20T16:32:56.000+08:00
Signed-off-by: zhuangbowei.zbw &lt;zhuangbowei.zbw@alibaba-inc.com&gt;
diff --git a/pkg/snapshot/overlay.go b/pkg/snapshot/overlay.go
@@ -115,7 +115,7 @@ func DefaultBootConfig() *BootConfig {
 			Port:      9863,
 		},
 		MirrorRegistry:    nil,
-		WritableLayerType: "append",
+		WritableLayerType: "sparse",
 		DefaultFsType:     "ext4",
 		RootfsQuota:       "",
 		Tenant:            -1,
