diff --git a/cloud/bmaas/bmdb/model/migrations/1681980576_extra_shepherd_processes.down.sql b/cloud/bmaas/bmdb/model/migrations/1681980576_extra_shepherd_processes.down.sql
new file mode 100644
index 0000000..e01997f
--- /dev/null
+++ b/cloud/bmaas/bmdb/model/migrations/1681980576_extra_shepherd_processes.down.sql
@@ -0,0 +1,2 @@
+-- Not removing added enum values, as the 'up' migration has 'if not exists',
+-- and there is no harm in keeping unused enum values around.
\ No newline at end of file
diff --git a/cloud/bmaas/bmdb/model/migrations/1681980576_extra_shepherd_processes.up.sql b/cloud/bmaas/bmdb/model/migrations/1681980576_extra_shepherd_processes.up.sql
new file mode 100644
index 0000000..6e7c630
--- /dev/null
+++ b/cloud/bmaas/bmdb/model/migrations/1681980576_extra_shepherd_processes.up.sql
@@ -0,0 +1,6 @@
+-- Add two more process kinds, ShepherdAgentStart and ShepherdRecovery, for agent
+-- start and recovery by the shepherd respectively. These deprecate the previous
+-- ShepherdAccess process. The two processes mutually exclude each other.
+
+ALTER TYPE process ADD VALUE IF NOT EXISTS 'ShepherdAgentStart';
+ALTER TYPE process ADD VALUE IF NOT EXISTS 'ShepherdRecovery';
\ No newline at end of file