On Mar 9, 2011, at 8:44 AM, John Hodrien J.H.Hodrien@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@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