rn21200 disc export cancel

I have experimented with export/import, but not on the main volume a lot.  You can import an exported volume (including what was once a main volume, I believe) as another volume into a system that already has a volume with an OS partition, but I don't recall trying to import one to "nothing".  When the new NAS has nothing, you normally just move the drives without an export.

If you do get your volume back, you are going to have to restore protocols and permissions, BTW.  They get wiped on export (or maybe import) to assure compatibility with the importing system.  You also lose any apps.

Now, I have an idea that just might work if your volume is RAID1 (redundant).  This may make matters worse, so should probably be a last ditch effort.  But, if you use another drive (any size) to re-initialize the NAS and turn off XRAID, then power down and insert one drive from the old volume, it may import the old (but now degraded because you are using only one of the two drives) volume when you power on.  Note that for that to have a chance to work, you'll have to make sure the volume name on the new drive is not the same as the old one (normally "data") and no shares have the same name (at least that you care to recover data from).  That typically means destroying the default "data" volume after initialization and manually creating a new one with a different name.