Can I directly write data to USB devices from MyCloud NAS?

I have more than 10TB worth of files stored on an old My Cloud EX2 Ultra unit. It has two USB 3.0 ports at the back. Yet, I don’t see an option to copy anything from the WD NAS unit to the USB device. Please confirm the only option is to use the Ethernet connection.

The EX2 Ultra unit started to complain about “File System Check Failed” regularly. It wants me to “backup the data” and recreate the RAID setup.

To my understanding, USB 3.0 is at least 2 times faster than the 1Gbps ethernet connection? I tested an old HDD with a USB 3.0 adapter, and got around 200 Mb/s for both sequential read and write performance when testing with CrystalDiskMark. With 1Gbps, the throughput can be at best 100 Mb/s.

Looks like I need to install an app called “USB Backups”. I can then create a job to copy things in either direction: NAS to USB or USB to NAS.

If you haven’t done so already, you may want to review the My Cloud OS5 User Manual which has a section specifically covering USB drives and how to backup a My Cloud to one attached to a My Cloud running the OS5 firmware.

My Cloud OS5 Online User Manual

Also, when using OS5 firmware, if one is trying to use the web portal or the WD My Cloud app for iOS/Android to copy content from one location to another within their My Cloud and they do not see a Share listed in the web portal or mobile app one may have to use the My Cloud Dashboard to enable Mobile/Web Share access on the missing Share. See the following WD Knowledgebase article for more information.

My Cloud OS5: Cannot See Shares in Web or Mobile App

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The USB Backup tool is not reliable, if functional at all. Here is what I have experienced:

  1. It failed to copy two files totaling 1TB, one is 600GB and the other is 400 GB. These are images of my boot drives. The process was terminated midway, with minimal troubleshooting information.
  2. While the copying job can be scheduled, the USB Backup tool does not report the read/write speed. All it got was a progress bar.

Since copying from the internal share failed, I cannot guess how fast it went. I’ll fall back to copying through Ethernet then.

Here is the “details” provided for the failed copy task:

Another option is to copy via SSH access.

I use a program called WinSCP for this work - although admittedly I don’t use it often.

I believe the program must stay running on your PC; but the heavy lifting is done by the NAS. There are ways around this limitation, but I have not looked into it.

Sorry - I am not an expert on this, but I know it can be done.

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The workaround is to issue nohup with the rsync or cp/mv command when using SSH. That way the command(s) issued via SSH will continue running when the SSH terminal connection is closed. Lengthy explanation was posted in another WD support subforum about this issue a little over a month ago.

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@NAS_user @Bennor Thanks a lot for your suggestions. After falling back to the Ethernet connection, I guess it opens a lot of possibilities for copying. Yet, if I have done the math correctly, all methods are subject to the speed limit of the1Gbps Ethernet port, which translates into 100Mb/s.

With an HDD candy having sequential writing speed of 200Mb/s over USB 3.0, if there can be such direct USB connection, the copying speed can be doubled.

I am currently copying through mapped network drive using a Windows 10 desktop machine. So far, Total Commander has reliably copied some 1.5TB in 5-8 hours. I can live with this rate. (I have an old unit of EX2 Ultra, which overheat itself when I first copied using native Windows File Explorer. Adding a blowing fan helped me to get out the 1/10 of the data. I am trying to stay away from a faster copying rate now :slight_smile:.)

Speaking of copying over network drives, robocopy can be a very strong contender as well? I use the following flags when copying from drive A to Drive B.

robocopy A:\Dir_A B:\Dir_A_copy /MIR /r:5 /fp /np

Yes some of the My Cloud Dashboard backup options were a bit half baked. They worked but you never knew when it wouldn’t.

Personally, I went to using CRON and scripting the backup (file copy) from the main My Cloud drive to a USB drive attached to the My Cloud’s USB port. Even scripted it to send me an email when finished. Set the CRON job to run on scheduled days/times. The advantage was I could control what I backed up rather than it being an all or nothing affair with the WD method. We had a number of discussions on alternatives to WD’s backup option in the single bay OS3 My Cloud subforum years back. Should work on multi bay units but not sure if it would work under OS5 firmware.

The main downside to using Teracopy (good program use it myself on occasion) to using WinSCP to using Windows File Explorer or Mac Finder to connecting the USB drive to the Windows/Mac computer to copy files is one will have to leave that computer running for the entire time of the backup/copy process. For a large amount of content that could take many hours or even days. Depending on the method used one may not be able to use the computer for any other purpose during that backup/copy process (computer may be sluggish doing other tasks).

That’s why the nohup command issued with the backup/copy command via SSH is (for some) a better way to go if one doesn’t want to use a scripted CRON job on the My Cloud itself. Both ways (nohup and CRON) will run entirely on the My Cloud. For some this is a better way to go than using a computer that has to be left running for many hours or days.

TeraCopy is super intuitive to use and easy to set up. Thanks a lot for the introduction. It copies loose files a lot faster than the stock Copy tool from Total Commander.

I unplugged the power cord accidentally. To my great joy and surprise, TeraCopy was able to catch back on after my EX2 Ultra unit got back online. @dswv42 Thanks again for the pointer! (Though, I don’t quite find a way to resume unfinished tasks when rebooting the machine where TeraCopy runs. I can at best skip the existing files…)

Personally one downside I see with using a computer and programs like Teracopy or any other file manager program to copy very large amounts of data from a NAS to a USB hard drive connected to that NAS is the very real issue that any sort of hiccup in that connection or with that computer may cause the copy to fail or stall. Been there, done that, very frustrating on very large data copying. Its one reason why I try to keep the large copy of data confined to the NAS operating system if I’m copying data from/to a USB hard drive connected to the NAS. Fortunately Synology which is now my main NAS includes several options of keeping the copy process within the NAS OS using the Synology DSM webGUI. The My Cloud OS/Dashboard typically doesn’t, which forces users to use various other methods to copying some of which includes keeping a computer on/connected the whole time. As we see some would rather keep it totally within the NAS OS. For others they don’t see it as an issue and have their own methods. YMMV

With this discussion one, who wasn’t aware of their options, has been presented various options to accomplish the transfer of data from/to USB hard drive that is directly connected to their My Cloud (or other NAS). With the information, one can made a better informed decision on which method to use; or they can search for other methods that better suit their needs.


Everyone has their own experiences and preferences. Never had a serious problem, that I can recall, with having my My Cloud copy files internally from the main hard drive to the USB hard drive. attached to the My Cloud, using SSH commands (or CRON). Have moved large amounts of data numerous times between the two devices over many years. Shrugs.

Circling back to the OP’s question, yes they can copy data from their EX2 Ultra hard drives to a USB hard drive attached to the Ultra’s USB port. They can use the My Cloud Dashboard app once installed, they can use SSH (putty, winscp, etc.), they can use Windows File Explorer, Teracopy or any other copy/file manager program. Or they can connected the USB drive to a computer and copy from the EX2 Ultra through the computer to the USB drive, again using Windows File Explorer, Tera copy or any number of other programs. One has options to choose from. Obviously we each, who have done this in the past with one’s own My Cloud’s, have a personal preference on what they/we would do to move the data. To each their own. :slightly_smiling_face:

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