Improve wording about Btrfs COW

diff --git a/index.html b/index.html
index a21b55937a74646cf9df22bd99ae3aae81b93803..31c5d34d1e27a5330b890a9513c964c6e4932350 100644 (file)
--- a/index.html
+++ b/index.html
@@ -257,9 +257,12 @@
   <h1>Btrfs offline dedupe [3.12]</h1>
   <ul class="incremental">
     <li>
-      Btrfs generally does COW rather than updating in-place, allowing
-      snapshots and file copies to defer the actual copying and save
-      space
+      Btrfs generally copies and frees blocks, rather than updating
+      in-place
+    </li>
+    <li>
+      This allows snapshots and file copies to copy-by-reference,
+      deferring the real copying until changes are made
     </li>
     <li>
       Filesystems may still end up with multiple copies of the same