MY Cloud EX4 - Freezes after Connecting External USB 3.0 Drive

MY Cloud EX4 - Freezes after Connecting External USB 3.0 Drive

My WD EX4 Hangs after a few mins when I connect a USB 3.0 External Drive that I
am trying to transfer Data from.
I have a 5TB Raid 5 Volume ( 4 x 2TB WD Drives ) and a USB backup Set to Auto transfer data from the External Drive
to the EX4 when it is connected.
The 5TB volume is almost empty, I have DLNA turned off along with anything else that could potentially be taking up CPU Bandwidth, Unable to log in via the Web Interface or via SSH,
SSH doesn’t even prompt me for login credentials, although I can ping without any problems
No issues there, lovely ping response time of 2ms.
I have upgraded to the latest firmware , however this was a waste of time.


Hello, what kind of External drive are you using? What is the size of the external drive drive? Are you able to access the drive via SSH without the external drive connected?


I am using a 2000 GB Seagate Desktop 7200rpm HDD ( Specs Below )
inside a Startech 3.5" USB 3.0 to SATA 3 HDD Enclosure with UASP Support.

I can Access the EX4 via SSH and HTTP when I Manually pull the power and reboot without the External drive Connected. This is the only way I can get it to respond.

Model: ST2000DM001
FW: CC25
WWN; 5000C5007AAF8F1C
Date: 15315

I Should also note that the 4 LED’s On the EX4 are flashing constantly with the external drive connected.
No messages is displayed on the LCD,
The LED on the external drive is steady / Constant
( This normally Flashes when Data is being accessed or written )
Current EX4 FW is: 2.11.140.

Exact same behaviour here, with a 6TB WD Red USB 3 drive. Used to work fine, I suspect the 2.11.140 update is the culprit.

This is a well documented “bug” with the software. The EX4 is scanning the drive for media and as a result thrashing a very small CPU. Twonky is the main culprit.

There is no fix.

As a workaround, turn off media scanning for attached drive and also DLNA serving. This disables Twonky and will liberate some CPU for you to use the attached drive.

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After 2 years of dealing with the WDEX4 and all the issues, some that have been addressed but many that will probably never get fixed unfortunately (does not speak well of the current state of the technology industry and quality of the workers), is there a thread here in this forum that combines all of the best approaches step by step to wrangle this NAS to work the best it can just as a simple device to do backups. I assume that many people like myself just wanted a way to do consistent and accurate backups of our data, and this NAS has never performed well or at all due to the poor specs and firmware bugs.

After 2 years now, I have almost given up on this device. But only recently did the USB backup option start to work for me, so even though it is pathetically slow, I could start backing up my data that was on my external USB drives. But today, this feature stopped working again, and I spent another 4 hours trying to figure out a workaround. Nothing I did seemed to resolve the issue, but it suddenly started working again after I noticed that the CPU was not pegged out doing something - who knows what. I do not know what caused the USB backup to start failing again due to the processes that were taking up all the CPU, but I am looking for a known resolution here to avoid wasting my time again when this happens in the future.

So if anyone can point the rest of us to a thread on this forum that has step-by-step procedure to kill all the processes on this NAS that cause it to fail to do just basic data transfer, it may help a lot of us get at least some use out of this device. The only other work-around that I have now is to wait for the NAS to go into a quiescent state after killing all the processes that I am aware of that I do not need like wdmcserverd and wdphotodmergerd before I start any backups.

I have worked around the issue by ignoring the GUI when needing to do backups. I do a monthly backup of all shares and then store it off-site. My work-around is:

  1. Turn off all media serving (via GUI)
  2. Plug in the USB Backup drive
  3. Leave it alone for an hour
  4. Fire up an SSH session to the EX4
  5. Copy and paste and execute my rsync commands for each share. If you need help on these fire off a backup using the GUI and then monitor using the “top” command. You can copy the command from there. Note: Modify the timeout timer to something sensible like 300 seconds (e.g. ‘rsync --timeout=300’)

It’s a pain, but it works reliably.