Missing physical disk and/or RAID disk at boot/reboot

Hello all.

Hardware: I'm running OMV 3 on my Odroid XU4 SOC. Using an USB3 to SATA convertor I've attached 2 physical disks (2 disks on 1 USB3 port).
Disk config: I've created a RAID mirror using the OMV interface.

Problem:

When cold booting: both physical disks are being detected (/dev/sda and /dev/sdb) but my RAID disk is missing (/dev/md127).
When rebooting from the OMV interface: 1 physical disk is detected (/dev/sda), the other one isn't (/dev/sdb). The RAID disk is detected (/dev/md127), but is marked as unhealthy due to the missing physical disk. When using the "scan" button in the OMV interface, the second physical disk is detected and I can restore my RAID disk using commandline.

Any ideas/suggestions/help would be welcome...

Except for this problem the system is running fantastic!

Thank you for your time!

Zitat von ryecoaaron

This seems to be a problem with most arm boards and usb drives in a a raid array. I think the boards boot fast enough that the usb drives aren't ready when array is supposed to be assembled. That is why I recommend not using mdadm arrays on arm boards or with usb drives. I know that isn't the answer you wanted but I haven't found a better one. Even adding/increasing bootwait/rootwait doesn't fix the issue.

I suspected as much... I was hoping an additional delay during the boot process would do the trick. However I first wanted to make sure that there are no other possible causes.

I would like to keep the software "out of the box", so fiddling with the boot process was a last resort anyway.

Thank you!