```go
func getAvailablePoolIdx(ctx context.Context) int {
        serverPools := z.getServerPoolsAvailableSpace(ctx)
        total := serverPools.TotalAvailable()
        // choose when we reach this many
        choose := rand.Uint64() % total
        atTotal := uint64(0)
        for _, pool := range serverPools {
                atTotal += pool.Available

	// Load latest rebalance status
	meta := &rebalanceMeta{}
	err = meta.load(ctx, z.serverPools[0])
	if err != nil {
		return r, err
	}

	// Compute disk usage percentage
	si := z.StorageInfo(ctx, true)
	diskStats := make([]struct {
		AvailableSpace uint64
		TotalSpace     uint64
	}, len(z.serverPools))
	for _, disk := range si.Disks {
		// Ignore invalid.

	meta := objLayer1.(*erasureServerPools).poolMeta
	pools := objLayer1.(*erasureServerPools).serverPools

	objLayer2, fsDirs, err := prepareErasurePools()
	if err != nil {
		t.Fatalf("Initialization of object layer failed for Erasure setup: %s", err)
	}
	defer removeRoots(fsDirs)

	newPools := objLayer2.(*erasureServerPools).serverPools
	reducedPools := pools[1:]
	orderChangePools := []*erasureSets{
		pools[1],
		pools[0],
	}

		// No need to fail upon Update() error, fallback to old value.
		cachevalue.Opts{ReturnLastGood: true, NoWait: true},
		func() (map[string]uint64, error) {
			m := make(map[string]uint64)
			for _, pool := range z.serverPools {
				for _, er := range pool.sets {
					// Load bucket usage prefixes
					ctx, done := context.WithTimeout(context.Background(), 2*time.Second)
					ok := cache.load(ctx, er, bucket+slashSeparator+dataUsageCacheName) == nil

	testShuffleDisks(t, z)
}

// Test shuffleDisks which returns shuffled slice of disks for their actual distribution.
func testShuffleDisks(t *testing.T, z *erasureServerPools) {
	disks := z.serverPools[0].GetDisks(0)()
	distribution := []int{16, 14, 12, 10, 8, 6, 4, 2, 1, 3, 5, 7, 9, 11, 13, 15}
	shuffledDisks := shuffleDisks(disks, distribution)
	// From the "distribution" above you can notice that: