Hi, we are presently running into a hotplug/linux-raid problem. Lets assume a hard disk entirely fails or a stupid human being pulls it out of the system. Several partitions of the very same hardisk are also part of linux-software raid. Also, /dev is managed by udev. Problem-1) When the disk fails, udev will remove it from /dev. Unfortunately this will make it impossible to remove the disk or its partitions from /dev/mdX device, since mdadm tries to read the device fail and will abort if this file is not there. Problem-2) Even though the kernel detected the device to not exist anymore, it didn't inform its md-layer about this event. The md-layer will first detect non-existent disk, if a read or write attempt to one of its raid-partitions fails. Unfortunately, if you are unluckily, it might never detect that, e.g. for raid1 devices. I think there should be several solutions to these problems. 1) Before udev removes a device file, it should run a pre-remove script, which should check if the device is listed in /proc/mdstat and if it is listed there, it should run mdadm to remove this device from the. Does udev presently support to run pre-remove scripts? 2.) As soon as the kernel detects a failed device, it should also inform the md layer. 3.) Does mdadm really need the device? Thanks, Bernd -- Bernd Schubert Q-Leap Networks GmbH - 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
