From mboxrd@z Thu Jan  1 00:00:00 1970
From: Francis Moreau <francis.moro@gmail.com>
Subject: Re: /sys/block/md126 still exists even after stopping the array
Date: Tue, 30 Sep 2014 09:43:17 +0200
Message-ID: <542A5F15.7030100@gmail.com>
References: <53A99B76.3020603@gmail.com>	<20140625110348.48ab2d7a@notabene.brown>	<54243ED7.6090904@gmail.com>	<20140926103348.5f5ea568@notabene.brown>	<54253E9F.4070505@gmail.com>	<20140926204445.1ec830b9@notabene.brown>	<54255A30.9010406@gmail.com>	<20140929143735.5fa54253@notabene.brown>	<54291C1D.7010005@gmail.com> <20140930075643.34e864fa@notabene.brown>
Mime-Version: 1.0
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 7bit
Return-path: <linux-raid-owner@vger.kernel.org>
In-Reply-To: <20140930075643.34e864fa@notabene.brown>
Sender: linux-raid-owner@vger.kernel.org
To: NeilBrown <neilb@suse.de>
Cc: linux-raid <linux-raid@vger.kernel.org>, sebastian.riemer@profitbricks.com
List-Id: linux-raid.ids

Hi Neil,

On 09/29/2014 11:56 PM, NeilBrown wrote:
> On Mon, 29 Sep 2014 10:45:17 +0200 Francis Moreau <francis.moro@gmail.com>
> 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 :-/

Thanks