On Mar 9, 2011, at 8:44 AM, John Hodrien <J.H.Hodrien at leeds.ac.uk> wrote: > On Wed, 9 Mar 2011, Ross Walker wrote: > >> On Mar 8, 2011, at 12:02 PM, John Hodrien <J.H.Hodrien at leeds.ac.uk> wrote: >> >>> The absolute definiton of safe here is quite important. In the event of a >>> power loss, and a failure of the UPS, quite possibly also followed by a >>> failure of the RAID battery you'll get data loss, as some writes won't be >>> committed to disk despite the client thinking they are. >> >> Don't forget about kernel panics and the accidentally pulled the plugs... > > Sure, but the kernel's always in a position to screw you over. While you're > being negative, include bad memory on the RAID card, and then your life > becomes really interesting. Life is full of risks one of course has to prioritize these from likely to unlikely and determine if mitigation of the likely risks is necessary. I have personally experienced kernel panics after a kernel upgrade, so I put that as likely, but have yet to experience RAID write-back corruption, so I put that as unlikely, but you never know. -Ross