TeraStation 5600D minimum number of HDD

[pearljam]

I am using the 6-bay model TS5600D. However, when two 2TB HDDs are installed and power is turned on, an error message "Boot Fail" is displayed. Is it because of the minimum number of HDD installed?

[1000001101000]

Installing the firmware often fails if you have less than 4 drives for that series device. There is a workaround for that issue if you want to install on less drives:
https://buffalonas.miraheze.org/wiki/Restoring_Stock_Firmware_without_TFTP#Notes_before_you_begin

That limitation is part of the firmware install process which takes place after a successful boot into EM mode/etc. "Boot Fail" usually means it failed to find a suitable drive to boot from.

can you share more information about your situation? Did these drives previously have the firmware/OS on them or is this a new install?

[pearljam]

Thank you for answer. It's a new installed drives.

[1000001101000]

Excellent.

There should be a tool for making a USB recovery key on the support page for this product. You can use that to create a boot disk you can use to install the stock firmware. If you run into trouble you can use that workaround I shared earlier to force the install on two disks.