Swapping smaller hard drive for larger one in EX4

Hello WD community,

I’ve recently purchased a WD My Cloud EX4 to expand my network storage. I was using a WDMyCloud 4TB unit to store all my digital media and wanted to replace it with something far more expandable. I purchased an empty EX4 unit and installed the only drives I had available (2TB, 1.5TB, 2x1TB). To get the most effective continuous storage space, I configured the drives in spanning mode and copied all my data from the 4TB unit to the EX4.

Now, I want to take the 4TB drive from the old WDMyCloud and replace one of the 1TB drives with it, and I’ve come across some unknowns:

  1. If I remove a 1TB drive from the EX4 and insert the 4TB, will the spanning configuration simply increase the size of the volume?

  2. Will I lose all data in the volume as the EX4 would need to rebuild the spanning configuration after introducing a new drive (and thereby format all the drives)?

  3. Since it is spanning, the 1TB potentially will have some files on it, can I simply plug this drive into any other PC and transfer the files back to the EX4?

I did look through the forums and I wasn’t able to find the answers I needed anywhere else. If someone has already asked these questions please point me in the right direction. I also called WD Support and the gentleman on the phone simply told me to check the internal backup section of the web UI for the answer. Unfortunately, I didn’t find anything there which addressed my concerns.

Thanks to anyone who can shed some light on this situation.

Welcome to the WD Community.

1) If I remove a 1TB drive from the EX4 and insert the 4TB, will the spanning configuration simply increase the size of the volume?

If you replace one of the drives, with the 4TB, the RAID will keep the size of the smallest unit on the enclosure.

2) Will I lose all data in the volume as the EX4 would need to rebuild the spanning configuration after introducing a new drive (and thereby format all the drives)?

You shouln’t loose any data since it will do the rebuild with the replacement drive.

3) Since it is spanning, the 1TB potentially will have some files on it, can I simply plug this drive into any other PC and transfer the files back to the EX4?

This might not be possible since the drive will have a specific format.

Hi ERmorel,

I just want to confirm, the drives are currently configured in Spanning mode. From my understanding, that means data will be written to all the drives in a round-robin fashion with no backup / redundancy. This is not a RAID configuration where I can simply remove 1 drive and have the EX4 rebuild the data from the other 3 (as far as I know, please correct me if my understanding of Spanning mode is incorrect).

That being said, I’m not sure your answers address my questions. Since the drives are not in RAID mode (of any sort), there won’t be any “smallest unit” to be kept as the drives are Spanning.

I should not lose any data that’s on the drive I remove, my concern is for the other 3 drives still in the unit, would I have to reformat them after changing 1 drive to the larger size.

As for the last response, I understand I may not be able to recover the data as it’s a specific format / file system. I’m hoping I can plug the drive into another UNIX/Linux interface and recover from there, but it’s a “do at my own risk” kind of thing.

If you could elaborate further I would appreciate it.

Thanks

You may be confusing your terms - but to be fair the terms JBOD & Spanning are sometimes used to mean the same thing.  When you say “spanning” I assume that you are NOT talking about JBOD, but about creating a Spanning set (per EX4 menu) - technically this is a variant of RAID 0 where each disk is appended to the previous disk. Disk 1 won’t be used until Disk 0 is filled up and so forth. This has bad performance as you will rarely read data off multiple disks, but allows you to recover data in the event of a breakage of the RAID members.  JBOD on the other hand is, as you describe, a combination of physical units where data is spread across all the units.

If you have a Spaning set then you can remove the disk, copy the data to your new drive and then re-install. HOWEVER I have not done this myself so it is ALWAYS advisable to have a full backup prior to any reconfiguration.  Most people only figure out how valuable their data is when it is gone.

Hi Skiwi,

Thanks for your response, you are correct, I am using Spanning and not JBOD.

When I removed the 1TB drive from the EX4 and put it into my HD Dock on my Windows 8.1 PC, the drive fails to read as the partitions are considered RAW format. Do you have any suggestions as to what file system is being used here?

I do understand the importance of data backups so I am backing up all my data before I proceed with the plan. It’s just taking a lot longer then I anticipated to transfer all my stuff from the EX4 to my backup. When it is done, I will proceed with swapping out the 1TB for the 4TB as you suggested and I’ll post my results here.

Thanks for all the helpful pointers.

The drives are not in Windows format (NTFS) but in Linux format (ext).  Spin up a VM to read, or mount on a Mac.

Also, you might want to check out  http://www.howtogeek.com/112888/3-ways-to-access-your-linux-partitions-from-windows/

Just wanted to let everyone know how my experience turned out in case anyone else has the same issue.

I backed up all my data (always), powered down the EX4 and removed the 1TB. After putting the 4TB back in and turning it back on, I was greeted with a “Volume 1 failure” message. Once I was able to get into the Web UI, my only option was to rebuild the spanning volume. This to me seems a little silly, but that could simply be because I don’t properly understand how Spanning works. My assertion was swapping one drive should not distroy the entire volume, but instead simply increase it’s size. This is NOT the case.

Going forward, I have configured all disks to JBOD which doesn’t give me the performance or reliability I want, but until I reach the end-state of having 4x4 TB drives this will ensure I don’t get stuck having to rebuild the Volume each time I remove a drive. With JBOD configuration, I can remove one and insert another while only affecting the data on that one volume and not wiping out the other three drives.

To sum it up, for consumers who purchase the EX4 empty with the intent of using whatever you have available and upgrading in the future, I would strongly recommend against using anything but JBOD until you have everything you need and can configure RAID properly. Swapping drives out is not a terribly simple process and requires a lot of time backing up and transferring data.

Did you not use the GUI to remove the disk?  I’ve not done this but would expect there to be an option to remove a disk from a spanning volume?

Hi Skiwi,

I did not see any option in the GUI to remove a disk. I assume by GUI you are referring to the web dashboard, there was no additional software with the EX4.

Yes, the Browser GUI - I would have assumed an option to add or remove volumes to the Spanning set, but I’ve got no way of seeing it (I’m Raid’ed).

If there isn’t an option, that is a sorely needed feature.