Want to copy my wd slim external hdd into my cloud ex2 ultra

I want to copy data (~800MB) from my WD Slim external HDD to a share which I have made in a 2tb WD red hdd installed in My Cloud EX2 Ultra. My Cloude EX2 Ultra is connected to my VDSL modem+Wifi Router via ethernet cable provided in the box,

My PC is connected VDSL modem+router via wireless connection

1st Try.) I connected my WD slim external HDD to USB3 port on my PC and then copied the whole content of external hdd and pasted it in the “Main Share”(the share which I created during setup of My Cloud EX2 ultra).
I was getting a transfer speed of 6 MB/s. and the transfer time was coming out to be more then a day.

2nd Try.) I connected the WD Slim External HDD directly into in of the 2 USB 3 ports present on the My Cloud EX2 Ultra. This time the transfer speed initially was >1MB/s, which after some time stablised to ~4MB/s. The estimated transfer time this time came out to be more the 1 day again.

What am I doing wrong. Where is the bottleneck in my setup. Why am I getting so much high transfer time and low transfer speeds.

Please help!!!

Did you try to use the USB to NAS backup option to copy data from USB device to NAS device?

https://support.wdc.com/knowledgebase/answer.aspx?ID=16540

Just went through the steps to copy the backup from USB to NAS. The backup job has started but there is no time shown on that page.

Ideally I should get at least > 50 MBps transfer speed when i copy data from my USB 3.0 external HDD connected to the My Cloud Ultra EX2 NAS, but I am only getting 2-4 MBps. I don’t understand this.

I don’t have to go through this whole USB to NAS backup process if I get good transfer speed. Please tell me the problem here.

Where is the bottleneck?? Since files are to to be directly transferred to NAS via USB3.0 port from an external USB3.0 HDD, I should get way more then 50+ MBps transfer speed. Its not like I am transferring files over network. 2-4 MBps speed is only justified when I transfer files over network as my modem+router has only 10/100 Ethernet port. So the maximum transfer speed from 100 Mbps lan post comes out to be 12MBps

The backup process couldn’t complete…it said that “USB device connected to WD my Cloud c can’t be recognised”…after 3 hours…

I re started the backup job again multiple times, but was getting the same error 15~20 minutes after starting the job