Convert user-old-node-size test to yarn

1 files changed, 19 insertions, 0 deletions

diff --git a/yarns/0030-basics.yarn b/yarns/0030-basics.yarn
index a2ae12fa..34cad9d2 100644
--- a/yarns/0030-basics.yarn
+++ b/yarns/0030-basics.yarn
@@ -207,3 +207,22 @@ create one. Test that such timestamps work.
     WHEN user U backs up directory L to repository R
     AND user U restores their latest generation in repository R into X
     THEN L, restored to X, matches manifest M
+
+Change B-tree node size
+-----------------------
+
+The setting for B-tree node size (`--node-size`) only affects new
+B-trees. Thus, if we've backed up with one size, and change the
+setting to a new size, the backup should still work.
+
+    SCENARIO backup with changed B-tree node size
+    GIVEN 100kB of new data in directory L
+    AND user U sets configuration node-size to 65536
+    WHEN user U backs up directory L to repository R
+    GIVEN 100Kb of new data in directory L
+    AND a manifest of directory L in M
+    AND user U sets configuration node-size to 4096
+    WHEN user U backs up directory L to repository R
+    AND user U restores their latest generation in repository R into X
+    THEN L, restored to X, matches manifest M
+    AND user U can fsck the repository R