diff --git a/lib/ceph b/lib/ceph
index 32a4760784..84640420df 100644
--- a/lib/ceph
+++ b/lib/ceph
@@ -36,7 +36,7 @@ CEPH_CONF_DIR=${CEPH_CONF_DIR:-/etc/ceph}
 # Ceph data. Set ``CEPH_LOOPBACK_DISK_SIZE`` to the disk size in
 # kilobytes.
 # Default is 1 gigabyte.
-CEPH_LOOPBACK_DISK_SIZE_DEFAULT=2G
+CEPH_LOOPBACK_DISK_SIZE_DEFAULT=4G
 CEPH_LOOPBACK_DISK_SIZE=${CEPH_LOOPBACK_DISK_SIZE:-$CEPH_LOOPBACK_DISK_SIZE_DEFAULT}
 
 # Common