}

	z := obj.(*erasureServerPools)
	er := z.serverPools[0].sets[0]

	erasureDisks := er.getDisks()
	ridx := rand.Intn(len(erasureDisks))

	z.serverPools[0].erasureDisksMu.Lock()
	er.getDisks = func() []StorageAPI {
		erasureDisks[ridx] = newNaughtyDisk(erasureDisks[ridx], nil, errFaultyDisk)
		return erasureDisks
	}
	z.serverPools[0].erasureDisksMu.Unlock()