diff --git a/storage/memory/peer_store.go b/storage/memory/peer_store.go
index 19a6c20..ecbf95a 100644
--- a/storage/memory/peer_store.go
+++ b/storage/memory/peer_store.go
@@ -12,7 +12,6 @@ import (
 	"time"
 
 	log "github.com/Sirupsen/logrus"
-	"github.com/prometheus/client_golang/prometheus"
 	"gopkg.in/yaml.v2"
 
 	"github.com/chihaya/chihaya/bittorrent"
@@ -23,44 +22,10 @@ import (
 const Name = "memory"
 
 func init() {
-	// Register Prometheus metrics.
-	prometheus.MustRegister(
-		promGCDurationMilliseconds,
-		promInfohashesCount,
-		promSeedersCount,
-		promLeechersCount,
-	)
-
 	// Register the storage driver.
 	storage.RegisterDriver(Name, driver{})
 }
 
-var promGCDurationMilliseconds = prometheus.NewHistogram(prometheus.HistogramOpts{
-	Name:    "chihaya_storage_gc_duration_milliseconds",
-	Help:    "The time it takes to perform storage garbage collection",
-	Buckets: prometheus.ExponentialBuckets(9.375, 2, 10),
-})
-
-var promInfohashesCount = prometheus.NewGauge(prometheus.GaugeOpts{
-	Name: "chihaya_storage_infohashes_count",
-	Help: "The number of Infohashes tracked",
-})
-
-var promSeedersCount = prometheus.NewGauge(prometheus.GaugeOpts{
-	Name: "chihaya_storage_seeders_count",
-	Help: "The number of seeders tracked",
-})
-
-var promLeechersCount = prometheus.NewGauge(prometheus.GaugeOpts{
-	Name: "chihaya_storage_leechers_count",
-	Help: "The number of leechers tracked",
-})
-
-// recordGCDuration records the duration of a GC sweep.
-func recordGCDuration(duration time.Duration) {
-	promGCDurationMilliseconds.Observe(float64(duration.Nanoseconds()) / float64(time.Millisecond))
-}
-
 type driver struct{}
 
 func (d driver) NewPeerStore(icfg interface{}) (storage.PeerStore, error) {
@@ -272,9 +237,14 @@ func (ps *peerStore) populateProm() {
 		s.RUnlock()
 	}
 
-	promInfohashesCount.Set(float64(numInfohashes))
-	promSeedersCount.Set(float64(numSeeders))
-	promLeechersCount.Set(float64(numLeechers))
+	storage.PromInfohashesCount.Set(float64(numInfohashes))
+	storage.PromSeedersCount.Set(float64(numSeeders))
+	storage.PromLeechersCount.Set(float64(numLeechers))
+}
+
+// recordGCDuration records the duration of a GC sweep.
+func recordGCDuration(duration time.Duration) {
+	storage.PromGCDurationMilliseconds.Observe(float64(duration.Nanoseconds()) / float64(time.Millisecond))
 }
 
 func (ps *peerStore) getClock() int64 {
diff --git a/storage/memorybysubnet/peer_store.go b/storage/memorybysubnet/peer_store.go
index 08921b8..5234297 100644
--- a/storage/memorybysubnet/peer_store.go
+++ b/storage/memorybysubnet/peer_store.go
@@ -13,7 +13,6 @@ import (
 	"time"
 
 	log "github.com/Sirupsen/logrus"
-	"github.com/prometheus/client_golang/prometheus"
 	"gopkg.in/yaml.v2"
 
 	"github.com/chihaya/chihaya/bittorrent"
@@ -24,44 +23,10 @@ import (
 const Name = "memorybysubnet"
 
 func init() {
-	// Register Prometheus metrics.
-	prometheus.MustRegister(
-		promGCDurationMilliseconds,
-		promInfohashesCount,
-		promSeedersCount,
-		promLeechersCount,
-	)
-
 	// Register the storage driver.
 	storage.RegisterDriver(Name, driver{})
 }
 
-var promGCDurationMilliseconds = prometheus.NewHistogram(prometheus.HistogramOpts{
-	Name:    "chihaya_storage_gc_duration_milliseconds",
-	Help:    "The time it takes to perform storage garbage collection",
-	Buckets: prometheus.ExponentialBuckets(9.375, 2, 10),
-})
-
-var promInfohashesCount = prometheus.NewGauge(prometheus.GaugeOpts{
-	Name: "chihaya_storage_infohashes_count",
-	Help: "The number of Infohashes tracked",
-})
-
-var promSeedersCount = prometheus.NewGauge(prometheus.GaugeOpts{
-	Name: "chihaya_storage_seeders_count",
-	Help: "The number of seeders tracked",
-})
-
-var promLeechersCount = prometheus.NewGauge(prometheus.GaugeOpts{
-	Name: "chihaya_storage_leechers_count",
-	Help: "The number of leechers tracked",
-})
-
-// recordGCDuration records the duration of a GC sweep.
-func recordGCDuration(duration time.Duration) {
-	promGCDurationMilliseconds.Observe(float64(duration.Nanoseconds()) / float64(time.Millisecond))
-}
-
 type driver struct{}
 
 func (d driver) NewPeerStore(icfg interface{}) (storage.PeerStore, error) {
@@ -311,9 +276,14 @@ func (ps *peerStore) populateProm() {
 		s.RUnlock()
 	}
 
-	promInfohashesCount.Set(float64(numInfohashes))
-	promSeedersCount.Set(float64(numSeeders))
-	promLeechersCount.Set(float64(numLeechers))
+	storage.PromInfohashesCount.Set(float64(numInfohashes))
+	storage.PromSeedersCount.Set(float64(numSeeders))
+	storage.PromLeechersCount.Set(float64(numLeechers))
+}
+
+// recordGCDuration records the duration of a GC sweep.
+func recordGCDuration(duration time.Duration) {
+	storage.PromGCDurationMilliseconds.Observe(float64(duration.Nanoseconds()) / float64(time.Millisecond))
 }
 
 func (ps *peerStore) getClock() int64 {
diff --git a/storage/prometheus.go b/storage/prometheus.go
new file mode 100644
index 0000000..3eb8899
--- /dev/null
+++ b/storage/prometheus.go
@@ -0,0 +1,44 @@
+package storage
+
+import "github.com/prometheus/client_golang/prometheus"
+
+func init() {
+	// Register the metrics.
+	prometheus.MustRegister(
+		PromGCDurationMilliseconds,
+		PromInfohashesCount,
+		PromSeedersCount,
+		PromLeechersCount,
+	)
+}
+
+var (
+	// PromGCDurationMilliseconds is a histogram used by storage to record the
+	// durations of execution time required for removing expired peers.
+	PromGCDurationMilliseconds = prometheus.NewHistogram(prometheus.HistogramOpts{
+		Name:    "chihaya_storage_gc_duration_milliseconds",
+		Help:    "The time it takes to perform storage garbage collection",
+		Buckets: prometheus.ExponentialBuckets(9.375, 2, 10),
+	})
+
+	// PromInfohashesCount is a gauge used to hold the current total amount of
+	// unique swarms being tracked by a storage.
+	PromInfohashesCount = prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "chihaya_storage_infohashes_count",
+		Help: "The number of Infohashes tracked",
+	})
+
+	// PromSeedersCount is a gauge used to hold the current total amount of
+	// unique seeders per swarm.
+	PromSeedersCount = prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "chihaya_storage_seeders_count",
+		Help: "The number of seeders tracked",
+	})
+
+	// PromLeechersCount is a gauge used to hold the current total amount of
+	// unique leechers per swarm.
+	PromLeechersCount = prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "chihaya_storage_leechers_count",
+		Help: "The number of leechers tracked",
+	})
+)