USB Passport Ultra not seen by ReadyNas 10200

Mr Framer.

I Thank you for the query. I have done some more testing.

Here are the results. I made sure on each change that the USB cable was properly plugged in, since it apparently is in rebellion mode and will unplug itself.

My prefence was to use NTFS so I could access the Passport Backups via Windows 10.  However I was unable to consistently complete backups. Several times it stopped halfway through with no error message. I have a feeling, but could not verify, that ejection of the disk formatted as NTFS was not consistent. I felt this way because I could not get the disk to be re- recognised, even after a power off and power on of the ReadyNas.  I only had success in this after reformatting the disk on the Windows computer.

All these tests are on the rear upper USB Port. I believe its a USB3. 

I got similar results on the front port, but got tired of waiting. I think its a USB2.

EXT4  Disk.      Plugged In Disk 2.      NAS Recognised it.      Ejected Disk 2

BTRFS             Plugged In Disk 1.      Not Recognised.           NAS Turned off, then On

                                                                   Recognised.           Eject Disk 1. Unplugged Disk 1. Replugged in Disk 1

                                                                   Recognised.           Eject Disk 1. Unplugged Disk 1.

EXT4 Disk2      Plugged in Disk 2.             Recognised,           (Note. This is behavior I would expect if hot plug works)

                                                                                                   Eject Disk 2. Unplugged Disk 2.

EXT4 Disk 2     Replug in Disk 2.        Not recognised.             ( Note.  Wierd. Why recognised last time and not this)

                                                                                                   Unplugged Disk 2

BTRFS Disk 1  Plug in Disk 1              Not recognised.             UnPlugged Disk 1    

EXT4    Disk 2  Plug in Disk 2              Not recognised.             NAS turn off, then On.

                                                             Recognised.                  Reformatted Disk 1 from EXT4 to BTRFS ( a few seconds)

Run Backup Job From NAS to Disk 1. Change Access rights from Everyone to Admin. ( Why default to everyone? )

Start 2:34. End    3:02      Roughly 30 minutes for 50 Gigabytes.   Given how slow these disks are, that is incredible speed and much faster than NTFS, which  actually never finished. Backup job includes automatic eject when finished. I must admit I wonder if everything got copied.

From this point on, for about 5 cycles, the disks would not be recognised unless the NAS was turned off, then on. This was true whether the disks were connected before or after the power cycle. With the power cycle they were recognised everytime. Reminded me of TRSDOS.

These are my tentative conclusions.

On my system, backups using NTFS are unreliable. When they dont complete, I develop trust issues.

EXT4 and BTRFS both seem to work quickly. BTRFS  is much faster. I haven't been able to completely check integrity.

The NAS must have its power recycled in order to change back up disks. ( Hotplugging disks into the USB port worked once, and then it didnt work for the rest of my tests.)

Is this consistent with other experinces.

Thanks.

Larry