Upgrade EX2 Ultra to Pro Series PR4100 (same hard drives)

Hi, my current setup is an EX2 Ultra with two WD Red 10TB drives in RAID1. Looking to upgrade a bit, and the PR4100 seems to be a logical step. I’ve searched around for some answers, but am hopefully looking for a more solid confirmation.

Can my two current drives be migrated into the PR4100 without data loss? I would purchase a diskless PR4100, take the two drives out of the EX2 Ultra and put them into the PR4100. Would the transition be seamless? Then additionally, I’d like to add two more 10TB drives to the PR4100.

I found this article which makes it seem like I could then add the additional drives and switch from RAID1 to RAID 5 without data loss (or minimal risk of loss anyway).

In the end, I would have the PR4100 setup with 4x10TB drives in RAID5 and still maintain my data from the original two 10TB drives that were in my EX2 Ultra.

Please let me know if I’ve been clear enough, and if this should work or if I have overlooked something.

Thanks in advance!

Hi mk_drive,

Please refer to the link mentioned below and follow the RAID user guide for more clarification on RAID and migration.


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Just in case anyone searches this topic in the future - a follow up.

The goal: upgrade from EX2 Ultra to PR4100 (for a Plex server) using the two 10TB WD Red drives I already had in my EX2 without data loss, then add an additional two 10TB WD Red drives into bay 3 and 4 of the PR4100 and migrate to RAID5, giving me 30TB of usable storage space.

The process:

  • Shutdown my EX2 Ultra and swapped the drives into the PR4100, making sure to swap bay 1 into 1 and bay 2 into 2.

  • Connected and powered up the PR4100, went to the My Cloud setup website. Everything was detected and setup properly. LED display on the PR4100 said something like “RAID roaming enabled”.

  • PR4100 dashboard immediately prompted me that the two 10TB drives were from another WD NAS and asked if I wanted to use them as-is, I definitely clicked OK.

  • Installed Plex on the PR4100 from the dashboard. That was it. Literally. Everything worked immediately following that. My Plex library continued to function seamlessly. No media loss, no meta data loss, no reconfiguration. It was as if nothing had changed.

  • Now to add the two additional drives. Shut down PR4100, popped in new drives to bay 3 and 4. Powered back up.

  • Using the article above I followed the steps to migrate RAID1 to RAID5. Everything went well (exactly as indicated in the article, screen-for-screen), and I’m currently in the slow process of waiting for it to complete the process (25% and counting!)

All in all (fingers crossed that nothing goes wrong in these final hours), I am extremely pleased with how easy this upgrade was.

Did it worked
Because I have the same issue. From WD mirror with 2x2tb drives to WD PR410 4x2tb drives.

I do not wnat to end up loosing data.

Yes, the above method worked for me flawlessly. All data and my Plex server continued functioning without only minimal downtime when migrating to RAID5. Once it was complete everything was perfect.

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Just wanted to say thank you for this very detailed information.
I’m looking to do the exact same thing and this info is so very Helpful.

For my setup, I have to add one more step. My Ex2 Only has one drive set to JBOD.
So I purchased (2) brand new Red Drives and will make those RAID1 (Placed in the Ex2)

(It will be a few months before I get the PR4100, So I want to at least get my Drives setup and Data moved onto them… Then I’m looking to Follow your Steps. Moving the Drives to the PR4100 Then Eventually Adding (2) More Drives and Changing RAID1 to RAID5.

Doing it this way, (Saves me from putting out all the Cash at once)
And in the mean time, I will have an up and running BETTER NAS than before, While I slowly get the rest of the Parts.