On Monday February 26, drees76@xxxxxxxxx wrote: > On 2/26/07, Colin Simpson <csimpson@xxxxxxxxx> wrote: > > If I say, > > > > dd if=/dev/sda2 of=/dev/null > > > > where /dev/sda2 is a component of an active md device. > > > > Will the RAID subsystem get upset that someone else is fiddling with the > > disk (even in just a read only way)? And will a read error on this dd > > (caused by a bad block) cause md to knock out that device? > > The MD subsystem doesn't care if someone else is reading the disk, and Correct. It doesn't care if someone writes either. The thing you cannot do is open the device with O_EXCL. Mounting effectively uses O_EXCL, as does adding a swap device, fsck, and various other things that want to think they have exclusive access. > I'm pretty sure that rear errors will be noticed by the MD system, > either. :-) Your typing is nearly as bad as mine often is, but your intent is correct. If you independently read from a device in an MD array and get an error, MD won't notice. MD only notices errors for requests that it makes of the devices itself. NeilBrown - 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
