Set "reserved_space=1G" in newly-created storage nodes. Closes #1208.

docs/configuration.rst

@@ -359,6 +359,10 @@ Storage Server Configuration
     same thing. Likewise, "1MiB", "1024KiB", and "1048576B" all mean the same
     thing.
 
+    "``tahoe create-node``" generates a tahoe.cfg with
+    "``reserved_space=1G``", but you may wish to raise, lower, or remove the
+    reservation to suit your needs.
+
 ``expire.enabled =``
 
 ``expire.mode =``

src/allmydata/scripts/create_node.py

@@ -126,7 +126,7 @@ def create_node(config, out=sys.stdout, err=sys.stderr):
     storage_enabled = not config.get("no-storage", None)
     c.write("enabled = %s\n" % boolstr[storage_enabled])
     c.write("#readonly =\n")
-    c.write("#reserved_space =\n")
+    c.write("reserved_space = 1G\n")
     c.write("#expire.enabled =\n")
     c.write("#expire.mode =\n")
     c.write("\n")

src/allmydata/test/test_runner.py

@@ -213,6 +213,7 @@ class CreateNode(unittest.TestCase):
                 self.failUnless("\n[storage]\nenabled = false\n" in content)
             else:
                 self.failUnless("\n[storage]\nenabled = true\n" in content)
+                self.failUnless("\nreserved_space = 1G\n" in content)
 
         # creating the node a second time should be rejected
         rc, out, err = self.run_tahoe(argv)