roachtest: use local SSDs for disk-stall failover tests

The disk-stalled roachtests were updated in cockroachdb#99747 to use local SSDs.
This change broke the `failover/*/disk-stall` tests, which look for
`/dev/sdb` on GCE (the used for GCE Persistent Disks), but the tests
still create clusters with local SSDs (the roachtest default).

Fix cockroachdb#99902.
Fix cockroachdb#99926.
Fix cockroachdb#99930.

Touches cockroachdb#97968.

Release note: None.

pkg/cmd/roachtest/tests/disk_stall.go

@@ -47,6 +47,8 @@ func registerDiskStalledDetection(r registry.Registry) {
 	}
 	makeSpec := func() spec.ClusterSpec {
 		s := r.MakeClusterSpec(4, spec.ReuseNone())
+		// Use local SSDs in an attempt to work around flakes encountered when using
+		// SSDs. See #97968.
 		s.PreferLocalSSD = false
 		return s
 	}

pkg/cmd/roachtest/tests/failover.go

@@ -45,11 +45,20 @@ func registerFailover(r registry.Registry) {
 		failureModeDiskStall,
 	} {
 		failureMode := failureMode // pin loop variable
+		makeSpec := func(nNodes, nCPU int) spec.ClusterSpec {
+			s := r.MakeClusterSpec(nNodes, spec.CPU(nCPU))
+			if failureMode == failureModeDiskStall {
+				// Use local SSDs in an attempt to work around flakes encountered when
+				// using SSDs. See #97968.
+				s.PreferLocalSSD = false
+			}
+			return s
+		}
 		r.Add(registry.TestSpec{
 			Name:    fmt.Sprintf("failover/non-system/%s", failureMode),
 			Owner:   registry.OwnerKV,
 			Timeout: 30 * time.Minute,
-			Cluster: r.MakeClusterSpec(7, spec.CPU(4)),
+			Cluster: makeSpec(7 /* nodes */, 4 /* cpus */),
 			Run: func(ctx context.Context, t test.Test, c cluster.Cluster) {
 				runFailoverNonSystem(ctx, t, c, failureMode)
 			},
@@ -58,7 +67,7 @@ func registerFailover(r registry.Registry) {
 			Name:    fmt.Sprintf("failover/liveness/%s", failureMode),
 			Owner:   registry.OwnerKV,
 			Timeout: 30 * time.Minute,
-			Cluster: r.MakeClusterSpec(5, spec.CPU(4)),
+			Cluster: makeSpec(5 /* nodes */, 4 /* cpus */),
 			Run: func(ctx context.Context, t test.Test, c cluster.Cluster) {
 				runFailoverLiveness(ctx, t, c, failureMode)
 			},
@@ -67,7 +76,7 @@ func registerFailover(r registry.Registry) {
 			Name:    fmt.Sprintf("failover/system-non-liveness/%s", failureMode),
 			Owner:   registry.OwnerKV,
 			Timeout: 30 * time.Minute,
-			Cluster: r.MakeClusterSpec(7, spec.CPU(4)),
+			Cluster: makeSpec(7 /* nodes */, 4 /* cpus */),
 			Run: func(ctx context.Context, t test.Test, c cluster.Cluster) {
 				runFailoverSystemNonLiveness(ctx, t, c, failureMode)
 			},