Transfer files to USB Drive

I have two 1 TB WD My Cloud drives attached to my home network. My network is an Apple Airport Extreme. My computer is a MacBook pro. The two WD drives have only 1 USB port between them. It is used to connect the two WD drives together. Therefore, I can’t connect an external USB drive directly the WD drives. I want to transfer files to the external drive then wipe my MacBook pro and WD drives and re-image the MacBook and re-install WD MyCloud.
How do I do that?

Let me make sure I understand – you have two WD My Cloud NASes, and you’ve got a USB cable connecting both of them together?

If that’s what you meant, then: why? That cable isn’t going to do anything for you.

The single bay/single drive My Cloud units do not work like that. The USB port is for attaching USB hard drives to it, NOT for attaching it to another My Cloud or to a computer. The My Cloud is a network attached storage device (NAS), NOT a external USB hard drive.

It is not quite clear what you are attempting to achieve. Why would you want to wipe the WD My Cloud devices?

Why not use Apple’s Time Machine to backup the MacBook Pro to the My Cloud (or use a third party backup program to backup the Mac to the My Cloud). Then wipe the Mac and load the backup from Time Machine or third party backup software?

If you really want to wipe both the two My Cloud drives and the Mac, then backup the files on both to a separate USB hard drive that is large enough to hold all the backups. Then wipe the three devices and reinstall the files to all three devices from the USB hard drive. Or backup everything to one of the two My Cloud devices, wipe the Mac and the one My Cloud and restore the backup from the other My Cloud.

Thank you for your reply. I always wondered on which MyCloud drive the Time Machine
backups and my other files were kept. I had no idea the two drives could not work in tandem. Your response clears up a lot of questions I have had. Is there a way to take advantage of the other My Cloud device e.g. can I have both of them connected to my network? One would be used for Time Machine backups the other for off-loading photos and music.

The reason I want to wipe them all clean is because my MacBook is running slow and My Cloud backup via Time Machine take 3-4 days for < 200GB. I’m running macOS High Sierra 10.13.6. I’ve seen some articles that say My Cloud and macOS High Sierra and Mojave. So I was thinking there could be some malware that snuck in on my MacBook. Therefore, any backups would likely have the malware also embedded in it.

Yes you can run two (or more) My Cloud devices on the same local network. You just have to give each of them a unique name. You should have NO problem using Time Machine to backup to one My Cloud and use the other My Cloud for photos/music/video etc. In reality you can use both My Cloud devices for media storage.

If you haven’t done so already you should read the My Cloud User Manual (https://support.wdc.com/product.aspx?ID=904)to learn more about how the device works and how to use it’s various features.

There are a number of causes for slow backups. Most come down to network equipment and the speed between the My Cloud and the computer transferring the files too/from the My Cloud. Make sure the My Cloud is connected to a Gigabit capable router and make sure the computer is also connected via Gigabit network to that same router. Using WiFi often is slower than using a wired Ethernet Gigabit connection. When possible use a wired Gigabit connection.

Thank you for your response again. My Tech Support (son-in-law; IT developer) set it up for me. Most of the technical discussions are way over my head. I’ll read the articles you referenced.