diff --git a/doc/source/configuration.rst b/doc/source/configuration.rst
index d1144ae9ed..b4fff4f208 100644
--- a/doc/source/configuration.rst
+++ b/doc/source/configuration.rst
@@ -642,6 +642,12 @@ with ``VOLUME_BACKING_FILE_SIZE``.
   VOLUME_NAME_PREFIX="volume-"
   VOLUME_BACKING_FILE_SIZE=24G
 
+When running highly concurrent tests, the default per-project quotas
+for volumes, backups, or snapshots may be too small.  These can be
+adjusted by setting ``CINDER_QUOTA_VOLUMES``, ``CINDER_QUOTA_BACKUPS``,
+or ``CINDER_QUOTA_SNAPSHOTS`` to the desired value.  (The default for
+each is 10.)
+
 
 Keystone
 ~~~~~~~~
diff --git a/lib/cinder b/lib/cinder
index f3e243090b..cefb609676 100644
--- a/lib/cinder
+++ b/lib/cinder
@@ -286,6 +286,11 @@ function configure_cinder {
         iniset $CINDER_CONF DEFAULT allowed_direct_url_schemes $CINDER_ALLOWED_DIRECT_URL_SCHEMES
     fi
 
+    # set default quotas
+    iniset $CINDER_CONF DEFAULT quota_volumes ${CINDER_QUOTA_VOLUMES:-10}
+    iniset $CINDER_CONF DEFAULT quota_backups ${CINDER_QUOTA_BACKUPS:-10}
+    iniset $CINDER_CONF DEFAULT quota_snapshots ${CINDER_QUOTA_SNAPSHOTS:-10}
+
     # Avoid RPC timeouts in slow CI and test environments by doubling the
     # default response timeout set by RPC clients. See bug #1873234 for more
     # details and example failures.