diff --git a/bucket_map/src/bucket.rs b/bucket_map/src/bucket.rs
index ea00eebef..92737414d 100644
--- a/bucket_map/src/bucket.rs
+++ b/bucket_map/src/bucket.rs
@@ -91,6 +91,8 @@ impl<'b, T: Clone + Copy + 'static> Bucket<T> {
             Arc::clone(&stats.index),
             count,
         );
+        stats.index.resize_grow(0, index.capacity_bytes());
+
         Self {
             random: thread_rng().gen(),
             drives,
@@ -421,6 +423,10 @@ impl<'b, T: Clone + Copy + 'static> Bucket<T> {
     }
 
     pub fn apply_grow_index(&mut self, random: u64, index: BucketStorage) {
+        self.stats
+            .index
+            .resize_grow(self.index.capacity_bytes(), index.capacity_bytes());
+
         self.random = random;
         self.index = index;
     }
@@ -429,21 +435,31 @@ impl<'b, T: Clone + Copy + 'static> Bucket<T> {
         std::mem::size_of::<T>() as u64
     }
 
+    fn add_data_bucket(&mut self, bucket: BucketStorage) {
+        self.stats.data.file_count.fetch_add(1, Ordering::Relaxed);
+        self.stats.data.resize_grow(0, bucket.capacity_bytes());
+        self.data.push(bucket);
+    }
+
     pub fn apply_grow_data(&mut self, ix: usize, bucket: BucketStorage) {
         if self.data.get(ix).is_none() {
             for i in self.data.len()..ix {
                 // insert empty data buckets
-                self.data.push(BucketStorage::new(
+                self.add_data_bucket(BucketStorage::new(
                     Arc::clone(&self.drives),
                     1 << i,
                     Self::elem_size(),
                     self.index.max_search,
                     Arc::clone(&self.stats.data),
                     Arc::default(),
-                ))
+                ));
             }
-            self.data.push(bucket);
+            self.add_data_bucket(bucket);
         } else {
+            let data_bucket = &mut self.data[ix];
+            self.stats
+                .data
+                .resize_grow(data_bucket.capacity_bytes(), bucket.capacity_bytes());
             self.data[ix] = bucket;
         }
     }
diff --git a/bucket_map/src/bucket_stats.rs b/bucket_map/src/bucket_stats.rs
index 53419452a..e65672917 100644
--- a/bucket_map/src/bucket_stats.rs
+++ b/bucket_map/src/bucket_stats.rs
@@ -12,12 +12,20 @@ pub struct BucketStats {
     pub flush_file_us: AtomicU64,
     pub mmap_us: AtomicU64,
     pub find_entry_mut_us: AtomicU64,
+    pub file_count: AtomicU64,
+    pub total_file_size: AtomicU64,
 }
 
 impl BucketStats {
     pub fn update_max_size(&self, size: u64) {
         self.max_size.fetch_max(size, Ordering::Relaxed);
     }
+
+    pub fn resize_grow(&self, old_size: u64, new_size: u64) {
+        let size_change = new_size.saturating_sub(old_size);
+        self.total_file_size
+            .fetch_add(size_change, Ordering::Relaxed);
+    }
 }
 
 #[derive(Debug, Default)]
diff --git a/bucket_map/src/bucket_storage.rs b/bucket_map/src/bucket_storage.rs
index b69166eb8..ad64d8dfe 100644
--- a/bucket_map/src/bucket_storage.rs
+++ b/bucket_map/src/bucket_storage.rs
@@ -332,6 +332,7 @@ impl BucketStorage {
             };
         });
         m.stop();
+        // resized so update total file size
         self.stats.resizes.fetch_add(1, Ordering::Relaxed);
         self.stats.resize_us.fetch_add(m.as_us(), Ordering::Relaxed);
     }
@@ -368,6 +369,11 @@ impl BucketStorage {
         new_bucket
     }
 
+    /// Return the number of bytes currently allocated
+    pub(crate) fn capacity_bytes(&self) -> u64 {
+        self.capacity() * self.cell_size
+    }
+
     /// Return the number of cells currently allocated
     pub fn capacity(&self) -> u64 {
         1 << self.capacity_pow2
diff --git a/runtime/src/bucket_map_holder_stats.rs b/runtime/src/bucket_map_holder_stats.rs
index e116b0295..11404a485 100644
--- a/runtime/src/bucket_map_holder_stats.rs
+++ b/runtime/src/bucket_map_holder_stats.rs
@@ -422,6 +422,24 @@ impl BucketMapHolderStats {
                         .unwrap_or_default(),
                     i64
                 ),
+                (
+                    "disk_index_index_file_size",
+                    disk.map(|disk| disk.stats.index.total_file_size.load(Ordering::Relaxed))
+                        .unwrap_or_default(),
+                    i64
+                ),
+                (
+                    "disk_index_data_file_size",
+                    disk.map(|disk| disk.stats.data.total_file_size.load(Ordering::Relaxed))
+                        .unwrap_or_default(),
+                    i64
+                ),
+                (
+                    "disk_index_data_file_count",
+                    disk.map(|disk| disk.stats.data.file_count.load(Ordering::Relaxed))
+                        .unwrap_or_default(),
+                    i64
+                ),
                 (
                     "disk_index_find_entry_mut_us",
                     disk.map(|disk| disk