On Mon, Nov 16, 2009 at 03:20:12PM -0500, Greg Smith wrote: > Robert Schnabel wrote: > >Nope. Forgive my ignorance but isn't that what a UPS is for anyway? > >Along with a BBU controller. > > If you have a UPS *and* a BBU controller, then things are much > better--those should have a write cache that insulates you from the > worst of the problems. But just a UPS alone doesn't help you very much: > > 1) A UPS is built with a consumable (the battery), and they do wear > out. Unless you're proactive about monitoring UPS battery quality and > doing tests, you won't find this out until the first time the power goes > out and the UPS doesn't work anymore. Well the bbu is just another battery (ok some are capacitors but...) so the same caveats apply for a bbu raid card. We test ours every 6 months and fail them if they are less than a 5 day capacity (failure over a long weekend 3 days + 1-2 day(s) to fix the issue (replace power supply, mobo etc.)). -- -- rouilj John Rouillard System Administrator Renesys Corporation 603-244-9084 (cell) 603-643-9300 x 111 -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
