The Celerra ID is the Unique identifier for the Celerra Network Server. The first two strings are the model and model number and the last string is the backend storage serial number from which the Celerra boots. This serial number thus can be the backend CLARiiON or Symm array which contains the boot (system) or control LUNs - but this is not the Celerra TLA serial number. This Celerra ID is used to identify the Celerra in Events or CallHome messages.

If you look at the Celerra Manager - there are two fields - namely Celerra ID and Serial Number. The second field, i.e. the Serial number is the Top Level Assembly (TLA) serial number for the Celerra box - which is the same as /nas/sbin/serial command output.

Hope this helps in clearing any confusion.
Thanks,
Sandip