On Mon, 20 Mar 2023 07:50:35 -0700 Marc MERLIN <marc@xxxxxxxxxxx> wrote: > On Mon, Mar 20, 2023 at 03:36:39PM +0100, Mariusz Tkaczyk wrote: > > Hi, > > mdadm is unable to complete this task because it cannot ensure that it is > > safe to stop the array. It cannot open the array with O_EXCL. > > If it is mounted then it may hang if filesystem needs to flush some data. > > Thanks for the reply. The array was not mounted, that said, given that > it was fully down, there wasn't a way to flush the data if it had been > (cable problem to an enclosure, all the drives disappeared at once) > > > Please, try umount the array if it mounted somewhere and then try: > > > > # echo inactive > /sys/block/md6/md/array_state > > # echo clear > /sys/block/md6/md/array_state > > I can try this next time (already had to reboot), thanks. > > That said, mdadm should output a better message in this case > > > mdadm: /dev/md6 does not appear to be an md device > is clearly wrong > > Is that something easy to fix/improve? Oh, sorry my bad, please see the code: https://git.kernel.org/pub/scm/utils/mdadm/mdadm.git/tree/mdopen.c#n472 We are failing to "understand" the array: https://git.kernel.org/pub/scm/utils/mdadm/mdadm.git/tree/util.c#n229 It has nothing to do with open and O_EXCL. I didn't dig into to determine why. Anyway, now error seems to be reasonable but maybe we should be able to tract this array as valid? I requires more work and analysis so it is not simple fix. Thanks, Mariusz
