diff --git a/CHANGELOG-3.1.md b/CHANGELOG-3.1.md
index 29efcc130..a608dd964 100644
--- a/CHANGELOG-3.1.md
+++ b/CHANGELOG-3.1.md
@@ -17,6 +17,19 @@ Note that any `etcd_debugging_*` metrics are experimental and subject to change.
 
 - Add [`etcd_server_slow_read_indexes_total`](https://github.com/coreos/etcd/pull/9897) Prometheus metric.
 - Add [`etcd_server_quota_backend_bytes`](https://github.com/coreos/etcd/pull/9820) Prometheus metric.
+  - Use it with `etcd_mvcc_db_total_size_in_bytes` and `etcd_mvcc_db_total_size_in_use_in_bytes`.
+  - `etcd_server_quota_backend_bytes 2.147483648e+09` means current quota size is 2 GB.
+  - `etcd_mvcc_db_total_size_in_bytes 20480` means current physically allocated DB size is 20 KB.
+  - `etcd_mvcc_db_total_size_in_use_in_bytes 16384` means future DB size if defragment operation is complete.
+  - `etcd_mvcc_db_total_size_in_bytes - etcd_mvcc_db_total_size_in_use_in_bytes` is the number of bytes that can be saved on disk with defragment operation.
+- Add [`etcd_mvcc_db_total_size_in_bytes`](https://github.com/coreos/etcd/pull/9819) Prometheus metric.
+  - In addition to [`etcd_debugging_mvcc_db_total_size_in_bytes`](https://github.com/coreos/etcd/pull/9819).
+- Add [`etcd_mvcc_db_total_size_in_use_in_bytes`](https://github.com/coreos/etcd/pull/9256) Prometheus metric.
+  - Use it with `etcd_mvcc_db_total_size_in_bytes` and `etcd_mvcc_db_total_size_in_use_in_bytes`.
+  - `etcd_server_quota_backend_bytes 2.147483648e+09` means current quota size is 2 GB.
+  - `etcd_mvcc_db_total_size_in_bytes 20480` means current physically allocated DB size is 20 KB.
+  - `etcd_mvcc_db_total_size_in_use_in_bytes 16384` means future DB size if defragment operation is complete.
+  - `etcd_mvcc_db_total_size_in_bytes - etcd_mvcc_db_total_size_in_use_in_bytes` is the number of bytes that can be saved on disk with defragment operation.
 
 
 ## [v3.1.18](https://github.com/coreos/etcd/releases/tag/v3.1.18) (2018-06-15)
diff --git a/CHANGELOG-3.2.md b/CHANGELOG-3.2.md
index 1e1a64ed8..299d76ee9 100644
--- a/CHANGELOG-3.2.md
+++ b/CHANGELOG-3.2.md
@@ -16,6 +16,19 @@ Note that any `etcd_debugging_*` metrics are experimental and subject to change.
 
 - Add [`etcd_server_slow_read_indexes_total`](https://github.com/coreos/etcd/pull/9897) Prometheus metric.
 - Add [`etcd_server_quota_backend_bytes`](https://github.com/coreos/etcd/pull/9820) Prometheus metric.
+  - Use it with `etcd_mvcc_db_total_size_in_bytes` and `etcd_mvcc_db_total_size_in_use_in_bytes`.
+  - `etcd_server_quota_backend_bytes 2.147483648e+09` means current quota size is 2 GB.
+  - `etcd_mvcc_db_total_size_in_bytes 20480` means current physically allocated DB size is 20 KB.
+  - `etcd_mvcc_db_total_size_in_use_in_bytes 16384` means future DB size if defragment operation is complete.
+  - `etcd_mvcc_db_total_size_in_bytes - etcd_mvcc_db_total_size_in_use_in_bytes` is the number of bytes that can be saved on disk with defragment operation.
+- Add [`etcd_mvcc_db_total_size_in_bytes`](https://github.com/coreos/etcd/pull/9819) Prometheus metric.
+  - In addition to [`etcd_debugging_mvcc_db_total_size_in_bytes`](https://github.com/coreos/etcd/pull/9819).
+- Add [`etcd_mvcc_db_total_size_in_use_in_bytes`](https://github.com/coreos/etcd/pull/9256) Prometheus metric.
+  - Use it with `etcd_mvcc_db_total_size_in_bytes` and `etcd_mvcc_db_total_size_in_use_in_bytes`.
+  - `etcd_server_quota_backend_bytes 2.147483648e+09` means current quota size is 2 GB.
+  - `etcd_mvcc_db_total_size_in_bytes 20480` means current physically allocated DB size is 20 KB.
+  - `etcd_mvcc_db_total_size_in_use_in_bytes 16384` means future DB size if defragment operation is complete.
+  - `etcd_mvcc_db_total_size_in_bytes - etcd_mvcc_db_total_size_in_use_in_bytes` is the number of bytes that can be saved on disk with defragment operation.
 
 ### gRPC Proxy
 
diff --git a/CHANGELOG-3.3.md b/CHANGELOG-3.3.md
index a415f2f77..b57ed1273 100644
--- a/CHANGELOG-3.3.md
+++ b/CHANGELOG-3.3.md
@@ -17,6 +17,19 @@ Note that any `etcd_debugging_*` metrics are experimental and subject to change.
 
 - Add [`etcd_server_slow_read_indexes_total`](https://github.com/coreos/etcd/pull/9897) Prometheus metric.
 - Add [`etcd_server_quota_backend_bytes`](https://github.com/coreos/etcd/pull/9820) Prometheus metric.
+  - Use it with `etcd_mvcc_db_total_size_in_bytes` and `etcd_mvcc_db_total_size_in_use_in_bytes`.
+  - `etcd_server_quota_backend_bytes 2.147483648e+09` means current quota size is 2 GB.
+  - `etcd_mvcc_db_total_size_in_bytes 20480` means current physically allocated DB size is 20 KB.
+  - `etcd_mvcc_db_total_size_in_use_in_bytes 16384` means future DB size if defragment operation is complete.
+  - `etcd_mvcc_db_total_size_in_bytes - etcd_mvcc_db_total_size_in_use_in_bytes` is the number of bytes that can be saved on disk with defragment operation.
+- Add [`etcd_mvcc_db_total_size_in_bytes`](https://github.com/coreos/etcd/pull/9819) Prometheus metric.
+  - In addition to [`etcd_debugging_mvcc_db_total_size_in_bytes`](https://github.com/coreos/etcd/pull/9819).
+- Add [`etcd_mvcc_db_total_size_in_use_in_bytes`](https://github.com/coreos/etcd/pull/9256) Prometheus metric.
+  - Use it with `etcd_mvcc_db_total_size_in_bytes` and `etcd_mvcc_db_total_size_in_use_in_bytes`.
+  - `etcd_server_quota_backend_bytes 2.147483648e+09` means current quota size is 2 GB.
+  - `etcd_mvcc_db_total_size_in_bytes 20480` means current physically allocated DB size is 20 KB.
+  - `etcd_mvcc_db_total_size_in_use_in_bytes 16384` means future DB size if defragment operation is complete.
+  - `etcd_mvcc_db_total_size_in_bytes - etcd_mvcc_db_total_size_in_use_in_bytes` is the number of bytes that can be saved on disk with defragment operation.
 
 
 ## [v3.3.8](https://github.com/coreos/etcd/releases/tag/v3.3.8) (2018-06-15)