Is Jetson nano SDKManager only support 16GB target file system?

I am new to Jetson nano development system.
I installed the development SDK on host machine (Ubuntu 18) and target Jetson nano development kit successfully by using he SDKMnager. The MicroSD care size is 32GB. After installed and boots up the target, it shows the low disk pace warning window. I checked the disk space by sing GParted, it has only 16GB allocated to the file system. The rest 16 GB is unallocated. I can’t resize the file system as lots of small allocated blocks (mmclk0p2 to mmcblk0p14) between /dev/mmcblk0p1(ext4) and the unallocated bock.
I also can’t create a new partition it says “It is not possible to create more 14 primary partitions”. How can i sort it out?
Thanks