On Monday November 3, dledford@xxxxxxxxxx wrote: > > The in-kernel names are set by the kernel md code. Right now, it has a > simplistic test that checks if the device is partitionable, then sets > the kobject name to either md%d or md_d%d. The key point being that the > md code gets to set the kobject name, and it's the kobject name that is > used my udev. Don't get me wrong, I know changing this setup now would > break udev horribly, this being because udev current does > subsystem==block,kernel=="md*" to match all md devices. In order to > break from this, we would need to do something like > subsystem==block,subtype==md and skip any name check tests. Then we > could in fact use arbitrary names and udev and the rest of the system > would be fine. So, I'm not saying it would work today, but that doesn't > mean it couldn't be designed for and then implemented with a coordinated > change to the kernel and udev. That's an interesting idea. echo md_fred > /sys/modules/md_mod/parameters/new_array # /sys/block/md_fred magically appears with some random minor number # udev ignores it because md/array_state is 'clear' cd /sys/block/md_fred/md echo raid5 > level ..... echo active > array_state # udev gets a CHANGE event and creates /dev/md_fred, and/or # /dev/md/fred plus any partitions that are found. I think that we need to have the "md_" prefix. I don't want someone ever to be able to create and md array called "sda"! And I think this would work with udev today, though mdadm wouldn't make use of it, and could get confused if some other code did. Any code which parses /proc/mdstat and expects to see "md%d" there will also get confused. But this is the first idea I have seen that really gives some value in an alternate way for creating md arrays (alternate to just opening the block-special device). Thanks for the suggestion. 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
