diff --git a/dib/ironic-python-agent-ramdisk/README.rst b/dib/ironic-python-agent-ramdisk/README.rst
index d348823..6137abe 100644
--- a/dib/ironic-python-agent-ramdisk/README.rst
+++ b/dib/ironic-python-agent-ramdisk/README.rst
@@ -25,6 +25,9 @@ Beyond installing the ironic-python-agent, this element does the following:
   listen for raw data from stdin and write compressed data to stdout. Command
   can be with arguments.
 * Configures rescue mode if ``DIB_IPA_ENABLE_RESCUE`` is not set to ``false``.
+* By default, sets a maximum size for the ramdisk systemd journal to 15M. This
+  can be disabled by setting ``DIB_IPA_DISABLE_JOURNAL_MAX_LOG_SIZE`` to any
+  value which is not ``False``.
 
 This element outputs three files:
 
diff --git a/dib/ironic-python-agent-ramdisk/post-install.d/98-set-journal-config b/dib/ironic-python-agent-ramdisk/post-install.d/98-set-journal-config
new file mode 100755
index 0000000..727953c
--- /dev/null
+++ b/dib/ironic-python-agent-ramdisk/post-install.d/98-set-journal-config
@@ -0,0 +1,15 @@
+#!/bin/bash
+
+if [ "${DIB_DEBUG_TRACE:-0}" -gt 0 ]; then
+    set -x
+fi
+set -eu
+set -o pipefail
+
+DIB_IPA_DISABLE_JOURNAL_MAX_LOG_SIZE=${DIB_IPA_DISABLE_JOURNAL_MAX_LOG_SIZE:-False}
+
+if [[ "$DIB_IPA_DISABLE_JOURNAL_MAX_LOG_SIZE" == "False" ]]; then
+    # Default templates have a journal section already defined, and we don't use
+    # iniset by convention, so unless we really need to, we'll just append here.
+    echo "SystemMaxUse=15M" >> /etc/systemd/journald.conf
+fi