June 1999: Ebay is down for 22 hours, costs $2 million
“Technicians traced the main cause of the outage to a problem with the Sun Solaris operating system, which overwrote files and corrupted the Oracle database. The database, Version 188.8.131.52, recognized a data block in an incorrect format, and that caused the main hardware–a Sun E10000 server–to crash.”
“Shoddy planning played key role in eBay outages”
via HN discussion about recent Amazon.com outage - I haven’t yet seen a postmortem of that.