failed to check file system for volume... (metadata corruption)

…now what? I received a notification:

Message: [Shared Folders] The default shared folders (Public) do not exist. To restore these shared folders, go to “Control Panel > Shared Folders > Restore Default Shared Folders”.

Of course going there didn’t help anything - those folders don’t just disappear to ever be able to restore them. I went to storage and noticed the volume is not mounted, and that a check was recommended. Of course the check didn’t do anything, bailed out barely saying 1%. So this is my latest status.

The enclosure is healthy, the two RAID 1 disks are healthy as well. At the time of the failure the first message was the system running out of memory (???) during a backup job from GDrive. Only a few Mb should have been transferred, but by the timestamp I think HBS3 got hung for a few hours. The job was subsequently disabled to free up memory, together with pretty much everything running at the time. And then the scheduled restart happened and since then no volume anymore. I did the latest system update right now, there are a few apps not updated including HBS3 but I assume its because of the missing volume. The latest important message was:

[Pool 1] switch to read only due to possible metadata corruption, please contact customer service for repair.

Until something happens from there, any ideas what I could try?

Hello,
Have you upgraded the RAM on this NAS?
I would strongly advise you to submit a support ticket.

I never touched the box… and yes I also opened a ticket (no answer yet).