Hi Neil, Actually I made a silly presumption simply because MD is so fast compared to most of the hardware raids I am testing – so I simple presumed it was using write cache without really investigating it well enough Thank you for the feedback! On Fri, Dec 3, 2010 at 1:27 AM, Neil Brown <neilb@xxxxxxx> wrote: > On Thu, 2 Dec 2010 15:58:51 +0000 mark delfman <markdelfman@xxxxxxxxxxxxxx> > wrote: > >> Hi >> >> Is there any way to use an MD RAID in write through mode? I >> appreciate that there is a performance impact but this is important >> from a security prospective.... > > MD RAID does work in write-through mode. I have occasionally thought about > adding a write-back mode which would make sense now that we have a sensible > flushing infrastructure in Linux. But I haven't implemented it. > >> >> The likelihood is that I would use RAID0 (I know this sounds like a >> contradiction to the above, but the ‘drives’ are probably hardware >> RAIDs). But may use standard RAID6. > > RAID0 doesn't do any caching at all. > >> >> I cannot see any way to disable write cache in MD, but I am hopefully >> I am simply missing something obvious. > > Why do you think these is a write-behind cache in MD ?? > > NeilBrown > > > >> >> I appreciate any feedback.... >> >> Thanks, Mark >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-raid" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
