https://ivanluminaria.com/en/tags/architecture/Recent content in Architecture on Ivan LuminariaHugoenTue, 16 Dec 2025 08:03:00 +0100https://ivanluminaria.com/en/posts/oracle/oracle-data-guard/Tue, 16 Dec 2025 08:03:00 +0100https://ivanluminaria.com/en/posts/oracle/oracle-data-guard/<p>The client was a mid-sized insurance company. Three hundred employees, an in-house management application running on Oracle 19c, a single physical server in the ground-floor server room. No replica. No standby. No disaster recovery plan.</p> <p>For five years everything had worked. And when things work, nobody wants to spend money protecting against problems they&rsquo;ve never seen.</p> <h2 id="the-day-everything-stopped" class="relative group">The day everything stopped <span class="absolute top-0 w-6 transition-opacity opacity-0 -start-6 not-prose group-hover:opacity-100"><a class="group-hover:text-primary-300 dark:group-hover:text-neutral-700" style="text-decoration-line: none !important;" href="#the-day-everything-stopped" aria-label="Anchor">#</a></span></h2><p>On a Wednesday morning in November, at 8:47 AM, the primary data group&rsquo;s disk suffered a hardware failure. Not a logical error, not a recoverable corruption. A physical failure. The RAID controller lost two disks simultaneously — one had been degraded for weeks without anyone noticing, the other gave out suddenly.</p>