cluster: try to disable swap when check --apply (#1803)

pkg/cluster/manager/check.go

@@ -632,6 +632,15 @@ func fixFailedChecks(host string, res *operator.CheckResult, t *task.Builder) (s
 			"",
 			true)
 		msg = fmt.Sprintf("will try to %s, please check again after reboot", color.HiBlueString("disable THP"))
+	case operator.CheckNameSwap:
+		// not applying swappiness setting here, it should be fixed
+		// in the sysctl check
+		// t.Sysctl(host, "vm.swappiness", "0")
+		t.Shell(host,
+			"swapoff -a || exit 0", // ignore failure
+			"", true,
+		)
+		msg = "will try to disable swap, please also check /etc/fstab manually"
 	default:
 		msg = fmt.Sprintf("%s, auto fixing not supported", res)
 	}

pkg/cluster/operation/check.go

@@ -297,6 +297,7 @@ func checkMem(opt *CheckOptions, memInfo *sysinfo.Memory) []*CheckResult {
 	if memInfo.Swap > 0 {
 		results = append(results, &CheckResult{
 			Name: CheckNameSwap,
+			Warn: true,
 			Err:  fmt.Errorf("swap is enabled, please disable it for best performance"),
 		})
 	}