Thanks for the quick response. it is a really nice solution!
I choose another approach
https://www.amazon.com/Express-Expansion...USB-C&th=1
I hooked up a regular 2.5 inch SSD through SATA6.0 to USB3 cable. I can use regular SSD as rootfs now.
The PCIe x4 provide enough current to power an USB external SSD. no extra 5v power needed.
jzhang18@rockpro64:~$ df -h
Filesystem Size Used Avail Use% Mounted on
udev 1.9G 0 1.9G 0% /dev
tmpfs 388M 696K 387M 1% /run
/dev/sda1 116G 2.9G 108G 3% /
tmpfs 1.9G 23M 1.9G 2% /dev/shm
tmpfs 5.0M 4.0K 5.0M 1% /run/lock
tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup
/dev/mmcblk0p6 112M 10K 112M 1% /boot/efi
tmpfs 388M 4.0K 388M 1% /run/user/112
tmpfs 388M 20K 388M 1% /run/user/1001
I choose another approach
https://www.amazon.com/Express-Expansion...USB-C&th=1
I hooked up a regular 2.5 inch SSD through SATA6.0 to USB3 cable. I can use regular SSD as rootfs now.
The PCIe x4 provide enough current to power an USB external SSD. no extra 5v power needed.
jzhang18@rockpro64:~$ df -h
Filesystem Size Used Avail Use% Mounted on
udev 1.9G 0 1.9G 0% /dev
tmpfs 388M 696K 387M 1% /run
/dev/sda1 116G 2.9G 108G 3% /
tmpfs 1.9G 23M 1.9G 2% /dev/shm
tmpfs 5.0M 4.0K 5.0M 1% /run/lock
tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup
/dev/mmcblk0p6 112M 10K 112M 1% /boot/efi
tmpfs 388M 4.0K 388M 1% /run/user/112
tmpfs 388M 20K 388M 1% /run/user/1001