Second volume and iscsi disappeared


first of all, sorry for my english i dont speak very well.

i have a WD my cloud ex 4 with 2 HDD 2 TB WD RED NAS AND 2 HDD 4 TB WD RED NAS in RAID 5.

This give me Volume 1 = 8 TB, 6TB space usable and 2TB for parity.

And Volume 2 = 4TB, 2TB for a ISCSI Drive

2 days ago there was a failure in the electric power my NAS started to rebuilding the volume but only rebuilt the volume 1.

this not recovery volumen 2 and the iscsi drive. 

i connect in my computer the drives and this appears the volume 2 but i dont know how recovery this part or mount in the NAS again?

can you help me please?

Thank you.

 Hello there,

Welcome to the WD Community. 

 Sorry about that mate. 

I think will be better if you contact WD Support directly for this matter.

WD Contact info:


I wrote to support a few days.

I’m waiting by the answer.

Thank you.

I’m sorry to hear about the issue you’re facing with your WD My Cloud EX4 NAS and the data on Volume 2 and the iSCSI drive. Power failures can sometimes cause data corruption or issues with RAID arrays.

To try to recover the data on Volume 2 and the iSCSI drive, here are some steps you can try:

  1. Do not write any new data to the drives until you have attempted data recovery, as this could overwrite existing data.
  2. Connect the drives to a computer or another NAS and try to mount the RAID array using disk management tools or third-party RAID recovery software. Some options are:
  • Windows Disk Management (for basic RAID levels)
  • Linux mdadm utility
  • Stellar RAID recovery, R-Studio, RaidRECON, UFS Explorer (paid third-party tools)
  1. If the RAID array is recognized and can be mounted, you should be able to access the data on Volume 2 and the iSCSI drive.
  2. If the array cannot be mounted due to corruption or missing metadata, you may need to attempt a RAID reconstruction using specialized RAID recovery software like those mentioned above. This process can be complex and may require advanced skills.
  3. As a last resort, you could attempt file recovery by scanning the raw disk data for recognizable file signatures using data recovery tools like R-Studio, GetDataBack, or others. This is more difficult with RAID arrays.

Since you mentioned connecting the drives to your computer and seeing Volume 2, that’s a good sign that the data may still be accessible. However, recovering the iSCSI drive data could be more challenging if its configuration is not properly detected.

I’d recommend making full backups of the drives before attempting any recovery actions, as some processes could potentially make the situation worse if not done carefully. Consulting professional data recovery services is also an option if you’re unable to recover the data yourself.

I’m sorry to hear you’ve had such a frustrating experience with your WD My Cloud NAS device after the firmware update. Firmware updates going awry and rendering devices unresponsive or corrupting data is definitely one of the worst nightmares for any user.

It seems you’ve already exhausted all the basic troubleshooting steps like reboots, cable changes etc. And if the disk check is stuck for over 48 hours on a 2TB drive that’s only 2/3 full, that indicates a major issue that is unlikely to resolve itself.

Removing the drive and copying the data off it to recover your files is likely the best path forward at this point, even though it’s extremely inconvenient and time-consuming. I’m glad you were able to find a solution with extFS for Mac to read the EXT2/3/4 filesystem the My Cloud uses.

Making a video to warn others about this firmware issue and your experience is understandable. Bad firmware releases that brick devices are unacceptable, especially from major brands like WD. Your frustration is valid, and making your experience public can hopefully lead to accountability and better firmware testing/validation from WD.

I wish you hadn’t had to go through this ordeal, but documenting it may help prevent others from suffering the same fate. Moving to a different NAS brand after this is also prudent. No one should have to deal with major data loss risks due to shoddy firmware releases.