[Lustre-discuss] Failover / reliability using SAD direct-attached storage

[Mark Hahn]

> It seems an external fibre
> or SAS raid is needed,

to be precise, a redundant-path SAN is needed.  you could do it with 
commodity disks and Gb, or you can spend almost unlimited amounts on 
gold-plated disks, FC switches, etc.

the range of costs is really quite remarkable, I guess O(100x). 
compare this to cars where even VERY nice production cars are only 
a few times more expensive than the most cost-effective ones.

> as the idea of loosing the file system if one
> node goes down doesn't seem good, even if temporary.

how often do you expect nodes to fail, and why?

regards, mark hahn.