#1040638 Bothersome message every day from cron

Package:
mdadm
Source:
mdadm
Description:
Tool to administer Linux MD arrays (software RAID)
Submitter:
Klaus Ethgen
Date:
2026-03-08 23:25:01 UTC
Severity:
normal
Tags:
#1040638#5
Date:
2023-07-08 09:20:23 UTC
From:
To:
Since some days I get the following message every day:
mdadm: DeviceDisappeared event detected on md device /dev/md/md3
mdadm: DeviceDisappeared event detected on md device /dev/md/md2
mdadm: DeviceDisappeared event detected on md device /dev/md/md1
mdadm: DeviceDisappeared event detected on md device /dev/md/md0
mdadm: NewArray event detected on md device /dev/md0
mdadm: NewArray event detected on md device /dev/md1
mdadm: NewArray event detected on md device /dev/md3
mdadm: NewArray event detected on md device /dev/md2

This come from cron and the command `mdadm --monitor --scan --oneshot`.
(Which produce the same message.)

I never had any md device under /dev/md/*. They was always under
/dev/mdX.

And my /etc/mdadm/mdadm.conf has the following entries:
   ARRAY /dev/md0 metadata=0.90 UUID=xxxxxxxx:xxxxxxxx:xxxxxxxx:xxxxxxxx
   ARRAY /dev/md1 metadata=1.0 name=ikki:1 UUID=xxxxxxxx:xxxxxxxx:xxxxxxxx:xxxxxxxx
   ARRAY /dev/md2 metadata=1.0 name=ikki:2 UUID=xxxxxxxx:xxxxxxxx:xxxxxxxx:xxxxxxxx
   ARRAY /dev/md3 metadata=1.0 name=ikki:3 UUID=xxxxxxxx:xxxxxxxx:xxxxxxxx:xxxxxxxx

/proc/mdstat has the following:
   ~> cat /proc/mdstat
   Personalities : [raid1]
   md2 : active raid1 sda6[3] sdb6[2]
	 419430260 blocks super 1.0 [2/2] [UU]
	 bitmap: 0/2 pages [0KB], 131072KB chunk

   md3 : active raid1 sda7[0] sdb7[2]
	 419430208 blocks super 1.0 [2/2] [UU]
	 bitmap: 1/4 pages [4KB], 65536KB chunk

   md1 : active raid1 sda5[0] sdb5[2]
	 1073741632 blocks super 1.0 [2/2] [UU]
	 bitmap: 0/8 pages [0KB], 65536KB chunk

   md0 : active raid1 sdb1[1] sda1[0]
	 1998976 blocks [2/2] [UU]

   unused devices: <none>

So it is strange where this "DeviceDisappeared" is coming from. Nowhere
in my system is a mentioning /dev/md/mdX.

#1040638#10
Date:
2023-07-08 14:41:14 UTC
From:
To:
Hi,

Am Sa den  8. Jul 2023 um 14:18 schrieb Daniel Baumann:

Well, first, I don't have systemd and will never ever have!

But it doesn't matter if Debian removed that cron job. It is mdadm
itself that prints the error:
   ~> mdadm --monitor --scan --oneshot
   mdadm: DeviceDisappeared event detected on md device /dev/md/md3
   mdadm: DeviceDisappeared event detected on md device /dev/md/md2
   mdadm: DeviceDisappeared event detected on md device /dev/md/md1
   mdadm: DeviceDisappeared event detected on md device /dev/md/md0
   mdadm: NewArray event detected on md device /dev/md0
   mdadm: NewArray event detected on md device /dev/md3
   mdadm: NewArray event detected on md device /dev/md2
   mdadm: RebuildStarted event detected on md device /dev/md2
   mdadm: NewArray event detected on md device /dev/md1

So mdadm is broken in some sort.

Regards
   Klaus

#1040638#15
Date:
2023-07-08 14:40:42 UTC
From:
To:
Hi,

Am Sa den  8. Jul 2023 um 14:18 schrieb Daniel Baumann:

Well, first, I don't have systemd and will never ever have!

But it doesn't matter if Debian removed that cron job. It is mdadm
itself that prints the error:
   ~> mdadm --monitor --scan --oneshot
   mdadm: DeviceDisappeared event detected on md device /dev/md/md3
   mdadm: DeviceDisappeared event detected on md device /dev/md/md2
   mdadm: DeviceDisappeared event detected on md device /dev/md/md1
   mdadm: DeviceDisappeared event detected on md device /dev/md/md0
   mdadm: NewArray event detected on md device /dev/md0
   mdadm: NewArray event detected on md device /dev/md3
   mdadm: NewArray event detected on md device /dev/md2
   mdadm: RebuildStarted event detected on md device /dev/md2
   mdadm: NewArray event detected on md device /dev/md1

So mdadm is broken in some sort.

Regards
   Klaus

#1040638#20
Date:
2023-07-10 04:06:39 UTC
From:
To:
(Klaus, did you really mean to close this bug report with your last
message?  I'll go ahead and reopen it since I'm also affected by this
bug.)


From what I understand, this bug affects entries of the form `/dev/md0`
in `mdadm.conf`, and was introduced by commit 84d969be, which now always
looks for `/dev/md/$(basename)`, resulting in failures when attempting
to access the non-existent `/dev/md/md0`.

(Until this is resolved, a simple `../md0` symlink seems to do the job
as a temporary fix.)

#1040638#33
Date:
2023-11-04 07:22:22 UTC
From:
To:
Hi,

since some days, the warning gets even worse by naging me the name are
not POSIX. But my names _are_ fully POSIX conform with only ASCII
characters in the name!

Regards
   Klaus

#1040638#38
Date:
2026-03-08 23:23:08 UTC
From:
To:
I'm also seeing this on my trixie system. A number of other users have
reported this same issue elsewhere, particularly users of
OpenMediaVault after upgrading to OMV 8 (based on trixie)[1][2]. It
appears to be a regression introduced in
84d969be8f6d8a345b75f558fad26e4f62a558f6 upstream[3], which was first
included in 4.2+20230223-1. This was later fixed by
456c6bed0b9e0866c75f0f7c8579d5f4f3f3e966 upstream[4], which was first
included in 4.5-1. So in theory at this point, only trixie is impacted
by this anymore.

I tested applying 456c6bed0b9e0866c75f0f7c8579d5f4f3f3e966 onto the
4.4-11 sources on my trixie box (had to massage the patch a bit), and
it appears to correct the issue. I didn't try updating to 4.5, though
I would suspect that to work as well.
--- [1]: https://forum.openmediavault.org/index.php?thread/58088-mdadm-devicedisappeared-event-detected-on-md-device-dev-md-md0-since-upgrade-to/ [2]: https://forum.openmediavault.org/index.php?thread/58015-md-email-every-morning/ [3]: https://github.com/md-raid-utilities/mdadm/commit/84d969be8f6d8a345b75f558fad26e4f62a558f6 [4]: https://github.com/md-raid-utilities/mdadm/commit/456c6bed0b9e0866c75f0f7c8579d5f4f3f3e966