On Wed, Jul 27, 2011 at 02:16:52PM +1000, NeilBrown wrote: > > As mentioned earlier, Linux 3.1 will contain support for recording and > avoiding bad blocks on devices in md arrays. > > These patches are currently in -next and I expect to send them to Linus > tomorrow. > > Using this funcitonality requires support in mdadm. When an array is created > some space needs to be reserved to store the bad block list. > > I have just created an mdadm branch called devel-3.3 which provides initial > functionality. The main patch is included inline below. > > This only supports creating new arrays with badblock support. It also only > supports 1.x metadata. > > I hope to add support to add a bad block list to an existing 1.x array at > some stage, but support for 0.90 metadata is not expected to ever be added. > > If you create an array with this mdadm it will add a bad block log - you > cannot turn it off (it is only 4K long so why would you want to). Then as > errors occur they will cause the faulty block to be added to the log rather > than the device to be remove from the array. > If writing the new bad block list fails, then the device as a whole will fail. > > I would very much appreciate any reports of success of failure when using > this new feature. If you can make a test array using a known-faulty device > and can experiment with that I would particularly like to hear about any > experiences. > > Thanks, > NeilBrown > > git://neil.brown.name/mdadm devel-3.3 > > http://neil.brown.name/git?p=mdadm;a=shortlog;h=refs/heads/devel-3.3 How is it implemented? Does the bad block get duplicated in a reserve area? Or are also corresponding good blocks on other sound devices also excluded? How big a device can it handle? If a device fails totally and the remaining devices contain devices with bad blocks, will there then be lost data? Best regrads keld -- 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
