diff --git a/README.md b/README.md
index 1a36db2..4e21df2 100644
--- a/README.md
+++ b/README.md
@@ -177,6 +177,15 @@ $ GC_INITIAL_HEAP_SIZE=4g nix-env -f ./outpaths.nix -qaP --no-name --out-path --
 
 # Running a builder
 
+It is recommended to create a special user for the ofBorg operation.
+This user should have git configuration for default username/email for
+non-interactive merges. For example:
+```
+git config --global user.email "graham+cofborg@example.com"
+git config --global user.name "GrahamCOfBorg"
+```
+
+
 ```
 nix-shell ./shell.nix
 $ cd ofborg
@@ -209,6 +218,17 @@ they are only used in the backend processing tasks, and there is no
 need for them on builders. However, to update the list in
 config.known-users.json, run `./scripts/update-known-users.sh`.
 
+In case you have a non-trivial setup on Linux, make sure that the ofborg
+user has access to `dev/kvm`, as it is needed for running tests.
+
+If you want to run multiple builder instances on the same physical 
+machine please make sure they use different configs with different
+instance identity (same username/password is OK) and different 
+repository paths. Running two builders with the same config risks data
+corruption.
+
+See also: https://github.com/NixOS/ofborg/wiki/Operating-a-Builder
+
 ## old php stuff...
 
 Only Graham needs to do this, since I run the only remaining PHP
diff --git a/example.config.json b/example.config.json
index 87cd093..92e24b5 100644
--- a/example.config.json
+++ b/example.config.json
@@ -1,6 +1,6 @@
 {
     "runner": {
-        "identity": "grahamc-laptop"
+        "identity": "..."
     },
     "checkout": {
         "root": "/home/grahamc/.nix-test-rs"
@@ -16,5 +16,8 @@
         "virtualhost": "ofborg",
         "username": "...",
         "password": "..."
+    },
+    "feedback": {
+        "full_logs": true
     }
 }