Quoting Josh Berkus <josh@agliodbs.com>:
> The first and most important step for RAID performance with PostgreSQL is to
>
> get a card with onboard battery back-up and enable the write cache for the
> card. You do not want to enable the write cache *without* battery back-up
>
I'm curious about this -- how do you avoid losing data if a cache stick dies?
Without redundancy, whatever hasn't been destaged to the physical media vanishes
Dual-controller external arrays (HDS, EMC, LSI, etc.) tend to mirror (though
algorithms vary) the cache in addition to battery backup. But do onboard arrays
tend to do this as well?
Mark