Is the single shelf attached to 8b on the SCSI card? I believe the instructions say it has to be attached to 8a first. I might be wrong, but the message is very similar to those I've seen if you have the shelves cabled incorrectly. I've never seen a system with one shelf, but I recall than on a system with 4 shelves (2 chains) you couldn't, for example, put one on one SCSI card and one on the other SCSI card. The 630 with the new shelves is much more sensitive to this than previous filer models.
It shouldn't be a problem in normal operation, but it could result in the filer getting confused if there is a disk failure or you try to do a hot swap of a drive, etc.
Sorry, I guess I should have said that I have 1 chain. Physically there are two shelves. NetApp engineer installed the shelves. I suppose he could have gotten it wrong.
-Rasmus