Replaces 2TB with 3TB but only sees 2TB

Hi,

I have a ReadyNAS Duo v2 running v5.3.7. My configuration was Flex-RAID in JBOD, where I had separate c and d volumes. Both drives were 2 TB. I use a second NAS to do the backup through Rsync once a day. Last week, the second hard drive failed. I replaced it with a 3TB one. The problem is the NAS recreated the d volume but only 2TB in size. There is 1TB wasted. How do I do it to have the second volume use the full 3TB?

Here is the last lines of user.log

Dec 6 18:57:32 NAS-2 RAIDiator: System is up.
Dec 6 18:59:45 NAS-2 RAIDiator: New disk detected. If multiple disks have been added, they will be processed one at a time. Please do not remove any added disk(s) during this time. [Disk 2]
Dec 6 18:59:56 NAS-2 RAIDiator: A new disk was added to the ReadyNAS. If multiple disks have been added, they will be processed one at a time. Please do not remove any added disk(s) during this time.
Dec 6 19:47:20 NAS-2 RAIDiator: Volume d created successfully.
Dec 6 20:09:09 NAS-2 shutdown[5869]: shutting down for system reboot
Dec 6 20:11:15 NAS-2 RAIDiator: System is up.