diff --git a/lib/ironic b/lib/ironic
index c6fa563e6a..9fb290f5ab 100644
--- a/lib/ironic
+++ b/lib/ironic
@@ -52,7 +52,11 @@ IRONIC_VM_SSH_PORT=${IRONIC_VM_SSH_PORT:-2222}
 IRONIC_VM_SSH_ADDRESS=${IRONIC_VM_SSH_ADDRESS:-$HOST_IP}
 IRONIC_VM_COUNT=${IRONIC_VM_COUNT:-1}
 IRONIC_VM_SPECS_CPU=${IRONIC_VM_SPECS_CPU:-1}
-IRONIC_VM_SPECS_RAM=${IRONIC_VM_SPECS_RAM:-256}
+# NOTE(agordeev): both ubuntu and fedora deploy images won't work with 256MB of RAM.
+#                 System halts and throws kernel panic during initramfs unpacking.
+#                 Ubuntu needs at least 384MB, but fedora requires 448.
+#                 So placing 512 here to satisfy both.
+IRONIC_VM_SPECS_RAM=${IRONIC_VM_SPECS_RAM:-512}
 IRONIC_VM_SPECS_DISK=${IRONIC_VM_SPECS_DISK:-10}
 IRONIC_VM_EMULATOR=${IRONIC_VM_EMULATOR:-/usr/bin/qemu-system-x86_64}
 IRONIC_VM_NETWORK_BRIDGE=${IRONIC_VM_NETWORK_BRIDGE:-brbm}