Hi Neil, On 09/30/2014 09:43 AM, Francis Moreau wrote: > Hi Neil, > > On 09/29/2014 11:56 PM, NeilBrown wrote: >> On Mon, 29 Sep 2014 10:45:17 +0200 Francis Moreau <francis.moro@xxxxxxxxx> >> wrote: >> >>>> So what were pids 930 and 459? >>>> One was presumably the "mdadm -Ss" - probably 930. >>>> Is 459 the "mdadm --monitor" ?? That might be useful hint. >>>> >>> >>> yes. >>> >>> [456] is: /sbin/mdadm --monitor --scan --daemonise --syslog >>> --pid-file=/run/mdadm/mdadm.pid >>> >>> and [930] is 'mdamd -Ss'. >> >> Good. Please try the patch below. >> > > After applying your patch, this is what I'm getting in syslog: > > Sep 30 03:40:07 localhost kernel: md_open(): md125 opened by mdadm [970] > Sep 30 03:40:07 localhost kernel: md_release(): md125 released by mdadm > [970] > Sep 30 03:40:07 localhost kernel: md_open(): md125 opened by mdadm [972] > Sep 30 03:40:07 localhost kernel: md_open(): md125 opened by mdadm [970] > Sep 30 03:40:07 localhost kernel: md_release(): md125 released by mdadm > [972] > Sep 30 03:40:07 localhost kernel: md_open(): md125 opened by > systemd-udevd [971] > Sep 30 03:40:07 localhost systemd[1]: Cannot add dependency job for unit > mdmonitor-takeover.service, ignoring: Invalid argument > Sep 30 03:40:07 localhost systemd[1]: Started Software RAID monitoring > and management. > Sep 30 03:40:07 localhost kernel: md_release(): md125 released by > systemd-udevd [971] > Sep 30 03:40:08 localhost mdadm[466]: DeviceDisappeared event detected > on md device /dev/md125 > Sep 30 03:40:08 localhost mdadm[466]: DeviceDisappeared event detected > on md device /dev/md126 > Sep 30 03:40:08 localhost mdadm[466]: DeviceDisappeared event detected > on md device /dev/md127 > Sep 30 03:40:08 localhost kernel: md125: detected capacity change from > 1863254016 to 0 > Sep 30 03:40:08 localhost kernel: md: md125 stopped. > Sep 30 03:40:08 localhost kernel: md: unbind<vdc3> > Sep 30 03:40:08 localhost kernel: md: export_rdev(vdc3) > Sep 30 03:40:08 localhost kernel: md: unbind<vdb3> > Sep 30 03:40:08 localhost kernel: md: export_rdev(vdb3) > Sep 30 03:40:08 localhost kernel: md_release(): md125 released by mdadm > [970] > Sep 30 03:40:08 localhost kernel: md_open(): md127 opened by mdadm [466] > Sep 30 03:40:08 localhost kernel: md_release(): md127 released by mdadm > [466] > Sep 30 03:40:08 localhost kernel: md_open(): md126 opened by mdadm [466] > Sep 30 03:40:08 localhost kernel: md_release(): md126 released by mdadm > [466] > Sep 30 03:40:08 localhost kernel: md_open(): md126 opened by mdadm [970] > Sep 30 03:40:08 localhost kernel: md_release(): md126 released by mdadm > [970] > Sep 30 03:40:08 localhost kernel: md_open(): md126 opened by mdadm [970] > Sep 30 03:40:08 localhost kernel: md126: detected capacity change from > 67043328 to 0 > Sep 30 03:40:08 localhost kernel: md: md126 stopped. > Sep 30 03:40:08 localhost kernel: md: unbind<vdc1> > Sep 30 03:40:08 localhost kernel: md: export_rdev(vdc1) > Sep 30 03:40:08 localhost kernel: md: unbind<vdb1> > Sep 30 03:40:08 localhost kernel: md: export_rdev(vdb1) > Sep 30 03:40:08 localhost kernel: md_open(): md127 opened by mdadm [466] > Sep 30 03:40:08 localhost kernel: md_release(): md127 released by mdadm > [466] > Sep 30 03:40:08 localhost kernel: md_release(): md126 released by mdadm > [970] > Sep 30 03:40:08 localhost kernel: md_open(): md127 opened by mdadm [970] > Sep 30 03:40:08 localhost kernel: md_release(): md127 released by mdadm > [970] > Sep 30 03:40:08 localhost kernel: md_open(): md127 opened by mdadm [970] > Sep 30 03:40:08 localhost kernel: md127: detected capacity change from > 214564864 to 0 > Sep 30 03:40:08 localhost kernel: md: md127 stopped. > Sep 30 03:40:08 localhost kernel: md: unbind<vdc2> > Sep 30 03:40:08 localhost kernel: md: export_rdev(vdc2) > Sep 30 03:40:08 localhost kernel: md: unbind<vdb2> > Sep 30 03:40:08 localhost kernel: md: export_rdev(vdb2) > Sep 30 03:40:08 localhost kernel: md_release(): md127 released by mdadm > [970] > > The ghost device is no more present so your patch seems to have fixed my > issue. But I must admit I don't really understand what's going on :-/ > Since those 'ghost' devices are expected from the MD implementation point of view, I'm wondering how am I supposed to detect them or maybe how an application is supposed to recognized online arrays. My application uses udev to detect et to get information about new devices. I don't think the information exported by udev is enough to figure this out. Also please note that since I rely on udev, I can't really read information on /sys since this information may be out of sync with the one returned by udev. Thanks. -- 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
