From c013b22f88dc6b1925149ac9ccc0e8449070a4cd Mon Sep 17 00:00:00 2001
From: Nick Travers <travers@cockroachlabs.com>
Date: Mon, 27 Mar 2023 22:19:29 +0000
Subject: [PATCH] roachtest: use persistent disks for disk-stall tests

Currently, the `disk-stall` tests use local SSDs. When run on GCE VMs, a
higher test flake rate is observed due to known issues with fsync
latency for local SSDs.

Switch the test to use persistent disks instead.

Touches: #99372.

Release note: None.
---
 pkg/cmd/roachtest/tests/disk_stall.go | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/pkg/cmd/roachtest/tests/disk_stall.go b/pkg/cmd/roachtest/tests/disk_stall.go
index a3349fdc0cb7..0c0918c986e0 100644
--- a/pkg/cmd/roachtest/tests/disk_stall.go
+++ b/pkg/cmd/roachtest/tests/disk_stall.go
@@ -45,12 +45,17 @@ func registerDiskStalledDetection(r registry.Registry) {
 			return &cgroupDiskStaller{t: t, c: c, readOrWrite: []string{"write"}, logsToo: true}
 		},
 	}
+	makeSpec := func() spec.ClusterSpec {
+		s := r.MakeClusterSpec(4, spec.ReuseNone())
+		s.PreferLocalSSD = false
+		return s
+	}
 	for name, makeStaller := range stallers {
 		name, makeStaller := name, makeStaller
 		r.Add(registry.TestSpec{
 			Name:    fmt.Sprintf("disk-stalled/%s", name),
 			Owner:   registry.OwnerStorage,
-			Cluster: r.MakeClusterSpec(4, spec.ReuseNone()),
+			Cluster: makeSpec(),
 			Timeout: 30 * time.Minute,
 			Run: func(ctx context.Context, t test.Test, c cluster.Cluster) {
 				runDiskStalledDetection(ctx, t, c, makeStaller(t, c), true /* doStall */)
@@ -76,7 +81,7 @@ func registerDiskStalledDetection(r registry.Registry) {
 					stallLogDir, stallDataDir,
 				),
 				Owner:   registry.OwnerStorage,
-				Cluster: r.MakeClusterSpec(4, spec.ReuseNone()),
+				Cluster: makeSpec(),
 				Timeout: 30 * time.Minute,
 				Run: func(ctx context.Context, t test.Test, c cluster.Cluster) {
 					runDiskStalledDetection(ctx, t, c, &fuseDiskStaller{
@@ -95,7 +100,7 @@ func registerDiskStalledDetection(r registry.Registry) {
 func runDiskStalledDetection(
 	ctx context.Context, t test.Test, c cluster.Cluster, s diskStaller, doStall bool,
 ) {
-	startOpts := option.DefaultStartOpts()
+	startOpts := option.DefaultStartOptsNoBackups()
 	startOpts.RoachprodOpts.ExtraArgs = []string{
 		"--store", s.DataDir(),
 		"--log", fmt.Sprintf(`{sinks: {stderr: {filter: INFO}}, file-defaults: {dir: "%s"}}`, s.LogDir()),
@@ -376,9 +381,9 @@ func (s *cgroupDiskStaller) device() (major, minor int) {
 	//    `cat /proc/partitions` and find `deviceName`
 	switch s.c.Spec().Cloud {
 	case spec.GCE:
-		// ls -l /dev/nvme0n1
-		// brw-rw---- 1 root disk 259, 0 Jan 26 20:05 /dev/nvme0n1
-		return 259, 0
+		// ls -l /dev/sdb
+		// brw-rw---- 1 root disk 8, 16 Mar 27 22:08 /dev/sdb
+		return 8, 16
 	default:
 		s.t.Fatalf("unsupported cloud %q", s.c.Spec().Cloud)
 		return 0, 0
@@ -455,7 +460,7 @@ func (s *fuseDiskStaller) Unstall(ctx context.Context, nodes option.NodeListOpti
 func getDevice(t test.Test, s spec.ClusterSpec) string {
 	switch s.Cloud {
 	case spec.GCE:
-		return "/dev/nvme0n1"
+		return "/dev/sdb"
 	case spec.AWS:
 		return "/dev/nvme1n1"
 	default: