"Scott Carey" <scott@xxxxxxxxxxxxxxxxx> 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 Get trained by Bruce Momjian - ask me about EnterpriseDB's PostgreSQL training!
