>
> If you have mirrored disks, and you write junk (e.g, because of
> a flaw in a fibre channel cable, something I have witnessed),
> then you have two perfectly fine copies of the junk.
>
Few years ago didn't this happen to Salesforce where a firmware bug corrupted the Disk, resulting in corruption of Oracle tablespace blocks
and all RAC nodes were equally useless since all of them read from the same disk. Salesforce lost 4 hours worth of data.