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user3728501
Asked: 2020-10-18 05:42:55 +0800 CST

Debian 10: mdadm raid superblocks "dissappear" after reboot?

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I'm very confused by some issues I'm having with a raid setup with mdadm.

I have a Debian 10 system, which I installed a KVM VM on, to use as a NAS server. I had problems with the raid superblocks dissappearing when rebooting, and never got to the bottom of the issue, so I started doing some more tests today, without the VM.

I tried to create a raid 1 array with mdadm on the host system. (Not on a VM)

I then rebooted the system, and again the raid superblocks appear to have dissappeared or somehow been wiped blank?

The system is using a LSI pci-e SAS card, flashed in IT mode, with a few 1TB Toshiba SATA drives.

Anyway, here's a list of commands run from this morning...

  184  sudo mdadm --create --verbose /dev/md0 --level=1 --raid-devices=2 /dev/sda /dev/sdb
  185  sudo mkdir -p /mnt/md0
  188  cat /proc/mdstat

At this point the raid finishes initializing

  189  sudo update-initramfs -u
  190  sudo mdadm --detail --scan | sudo tee -a /etc/mdadm/mdadm.conf 
  191  cat /etc/mdadm/mdadm.conf

Seems ok

  193  echo '/dev/md0 /mnt/md0 ext4 defaults,nofail,discard 0 0' | sudo tee -a /etc/fstab 
  194  sudo mount /dev/md0 /mnt/md0

Can read data on drives ok, still there from last raid configuration

  195  cat /proc/mdstat

... reboot, no md0 device started or mounted

  197  sudo mdadm --detail --scan

blank!

  198  cat /etc/mdadm/mdadm.conf 
  199  cat /proc/mdstat

blank!

  200  sudo mdadm --assemble --scan

does nothing

I'm extremely confused by what is going on here - and I have no clue how to start diagnosing the problem further.

debian raid mdadm

0 Answers