NO.
You need to backup all your data first but since your DNS-321 is dead than that won't work.
If you need the data on the JBOD set then you will need a USB/SATA adapter/caddy and some recovery software (R-Studio appears to work with JBOD sets) and enough disk space on your computer to build the virtual disk set.
When you have recovered as much of your data as possible put the disks in the new unit and format them as STANDARD disks (JBOD sets are fragile and you can lose all your data if one disk dies) and copy the data from the virtual disk set to the new unit - you have to decide what data goes on which disk.
You can make another JBOD set but you MUST be sure to make regular backups if your data is valuable to you.