Not able to remove a RAID6 array on /dev/md0 or remove XFS file system using this array.

I have a new server that is still in testing. I have a five disks in a Raid6 array using MD with a XFS file system on that /dev/md0 array. I want to remove/delete the array and try something different. My /dev/md0 raid6 array is still 'referenced' and therefor I can not delete it. I also can not delete/remove the XFS file system that using this array. How can I identify the 'reference' and delete it?

What I have done:

Removed NFS share using MD0 and also disabled NFS.

Removed all files and all folders that were on XFS share of /dev/md0

Removed the one SMB share that was using /dev/md0 and disabled 'Home Directory' in SMB just to be safe.

There are no more shares on MD0 XFS.

Tried to remove OMV->Storage->FileSystem-> XFS file system on dev/md0. The square button for remove is not highlighted.

Tried to remove /dev/md0 from OMV->Storage-->Multiple devices. The square button for remove is not highlighted.

Tried the command: sudo mdadm --stop /dev/dm0
Response:: Cannot get exclusive access to /dev/md0: Perhaps a running process, mounted filesystem or active volume group?

Ran OMV->Diagnostics->Report and got this: Full report is attached.

================================================================================

= Linux Software RAID
================================================================================
md0 : active raid6 sdb[1] sda[0] sdd[3] sdc[2] sde[4]
Personalities : [raid6] [raid5] [raid4] [linear] [multipath] [raid0] [raid1] [raid10]
md0 : active raid6 sdb[1] sda[0] sdd[3] sdc[2] sde[4] 35156259840 blocks super 1.2 level 6, 512k chunk, algorithm 2 [5/5] [UUUUU] bitmap: 0/88 pages [0KB], 65536KB chunk

I have run out thoughts on what is 'referencing' the /dev/md0 array.

How can I find the reference?

Can I somehow delete the file system and MD array without finding the reference?

Any help would be appreciated.

Thank you BernH. Sounds like the perfect solution. But .... There's a glitch.

What I did:

Found OMV-Extras and installed it.

Installed OMV-Reset-Permissions

Rebooted (just in case)

ran OMV-Reset-Permissions

* Sure enough - there were two permissions still linked to my /dev/Raid6 array

* Chose /dev/Raid6 and hit the reset icon

* on new window chose 'reset ACLs' checkbox to activate the reset button and then pressed the 'reset' button

* * received an error message about invalid parameters.

* Rebooted,OMV and tried again with same results.

Is this a glitch on my side or do I need to tell OMV-Reset-Permissions about this issue?

FYI - Note to others trying to get and install OMV-Extras and OMV-Reset-Permissions

1. To install OMV-Reset-Permissions you must first install OMV-Extras (Plug-Ins not supported by OMV that are not tested by OMV).

* The OMV-Extras web site is at: https://wiki.omv-extras.org/doku.php?id=misc_docs:omv_extras

* It will tell you to execute a command with 'root' privileges' to install OMV-Extras Use Putty or your favorite SSH tool.

* This is not as simple as just using sudo. Why: sudo works for only one command and this line has multiple commands. in it

** Option 1 - login as root (root has root permissions by, definition, until logged out)

** Option 2 - use "sudo -s" to get and retain root privileges with your regular ID until you logout

*** The command is: wget -O - https://github.com/OpenMediaVa…ckages/raw/master/install | bash

2. Install OMV-Reset-Permissions using OVM->System->Plugins

* The new plug-ins are now in the list.

3. Run OMV-Reset-Permissions using OMV->Services->Reset-Permissions

Solved:

Thanks BernH, I finally got it to work. My Raid6 array is gone and I have my five drives back for another test.

The reset permissions plugin finally showed nothing "in use by"/remaining on my raid6 array.

I still could not unmount the XFS file system from OMV_Raid6 or remove the OMV_Raid6 array from md. The icons were still greyed out.

Then I went back and looked at the usual suspects and found one share "/" remaining on OMV_Raid6. Then I deleted the "/" share.

Now I can select OMV_Raid6 in multiple devices and press the active delete icon. It worked.

Prior steps:
1. removed permissions to all files and folders on OMV_Raid6

2. removed all files and folders on OMV_Raid6

What I finally did:

1. Stopped all services shown in resetpermissions.

2. Turned off homedirectory (everywhere I could find references to it)

3. Uninstalled the filebrowser plugin from OMV. I could stop the service but it still showed as loaded and showed in resetpermissions.

4. Removed the share "/" to file system XFS on OMV_Raid6 (This was the last thing I did)

I could finally select OMV_Raid6 in Multiple Devices and used the now active delete icon.

I don't know how to mark this as solved.