On Thu, Apr 14, 2011 at 1:14 PM, Greg Smith <greg@xxxxxxxxxxxxxxx> wrote: > And the idea that a UPS is sufficient to protect against that even happening in > wildly optimistic. Note that the real danger in relying on a UPS is that most power conditioning / UPS setups tend to fail in total, not in parts. The two times I've seen it happen, the whole grid shut down completely for a few hours. The first time we had Oracle, Ingress, Sybase, SQL-Server, etc. etc. database server across the company corrupted. DAYS of recovery time, and since they all failed at once, the machines in replication got corrupted as well. Restoring production dbs from backups took days. The only machine to survive was the corporate intranet running pgsql on twin 15k SCSI drives with a proven reliable battery backed controller on it. It was mine. This was a company that lost something like $10k a minute for downtime. And the downtime was measured not in seconds, minutes or hours, but days because everyone had said the same thing, "The UPS and power conditioners make power plug pull survivability a non issue." When the only machine with an uncorrupted database is the corporate intranet server the 24/7 production guys look pretty stupid. They also suddenly decided to start doing power plug pull tests on all database servers. To make matters worse, the kind of system to NEED the higher throughput from SSDs is likely the kind of system to be the worst kind to suffer downtime due to corruption. OTOH, restores from backups should run pretty fast. :) -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
