[Beowulf] Surviving a double disk failure

[Stuart Midgley]

Thanks to all the responses, it has been interesting reading.  We have  
started using raid6 on newer servers and will slowely get rid of our  
old raid5 servers.

I found the comments about scrubbing very interesting.  What do people  
do with their file systems?  We couldn't afford the reduced  
performance and time for scrubbing.  We run our Lustre setup almost  
flat out all the time.  We regularly do over a PB of io in a week (we  
often have our total throughput at ~3GB/s for weeks on end).  We use  
lustre as our scratch space so backups are not possible.  Nothing  
could get the data off fast enough between us creating/using/deleting  
it.

Of course, the fact that we basically run at 95% full all the time is  
as good as scrubbing :)


-- 
Dr Stuart Midgley
sdm900 at gmail.com