"Scott Carey" <scott@richrelevance.com> writes:
> On Raid Controllers and Dev machines:
>
> For a dev machine the battery backup is NOT needed.
>
> Battery back up makes a _production_ system faster: In production, data
> integrity is everything, and write-back caching is dangerous without a
> battery back up.
>
> So:
> Without BBU: Write-through cache = data safe in power failure; Write back
> cache = not safe in power failure.
> With BBU : Both modes are safe on power loss.
This could be read the wrong way. With a BBU it's not that you can run the
drives in write-back mode safely. It's that you can cache in the BBU safely.
The drives still need to have their write caches off (ie, in write-through
mode).
--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com
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