On Thu, Dec 10, 2009 at 12:39:29AM -0500, nixlists wrote: > On Wed, Dec 9, 2009 at 11:54 PM, Marco Peereboom <sl...@peereboom.us> wrote: > >> What happens if the written data is not the same for some reason (and > >> what's the likelihood of this happening)? How does the OS and fsck > >> behave in this case? > > > > There is no way to quantify that. You are the one that needs to > > calculate the odds and see if they meet your expectations. > > > > No telling on fsck/OS; could be from silent data corruption to looking > > at a ddb prompt. > > So softraid can't detect if the data is written differently to the > drives? In what sort of cases would one expect the mirror to become > corrupt? Kernel crash? Hardware crash? Does softraid detect this? What > failures does it detect?
I must not be making myself clear. No, softraid can and will not detect that. Even if you know you only know that the data is bad; there are no other hints that can be deduced from that knowledge. This can happen when a drive returns corrupt data for whatever reason, be it hardware failure or a failed previous write etc. Let me repeat: No telling on fsck/OS; could be from silent data corruption to looking at a ddb prompt.
