This is my first time building my own RAID and I think something is messed up and I have no idea what to do next. I have looked all over the interwebs and have not found any solutions that help.
I have 3 x 4TB hard drives. Last night I installed Webmin to help me create a Linux Raid. I created a RAID5 and currently is is resyncing. After creating the RAID I attempted to create a filesystem of type ext4. I got an error
Error: The primary GPT table is corrupt, but the backup appears OK, so that will be used.
I assumed it would still work so I waited.. and waited... and waited. I did this command through Webmin and not in the console so I have no idea what happened after I tried to create it.
I also tried mounting the RAID
sudo mount /dev/md0 /mnt/raidmount/
and I got the error
mount: /mnt/raidmount: /dev/md0 already mounted or mount point busy.
I thought maybe I have to wait till the filesystem was finished, but it has now been 20 hours so I assume it would have finished.
When I run 'mount' it does not show /dev/md0 as already being mounted.
Eventually I got tired and decided to just delete the RAID and start over and use command line. But now I get the error
mdadm: Cannot get exclusive access to /dev/md0:Perhaps a running process, mounted filesystem or active volume group?
At this point I do not know what to do and can not remove, change or fix it.