Switching from EX4100 to PR4100

Purchased the EX4100 not long ago and it has been great except for a few transcoding issues/delays in Plex. I guess I should have waited because the PR4100 looks like a great upgrade in terms of processing power. So my questions are:

  1. Can I take/swap the drives out of the EX4100 and put them into a PR4100 chasis?
  2. Will I lose any data/need to reformat?
  3. If I do want to upgrade the hardware and the answer to #1 and 2 is no, what is the best approach to moving things over without having to shell out $$$ for new WD Red drives?

Thanks in advance for the help!

Edit: I did search the boards but since the PR4100 is a newer thing I didn’t get much (obviously). However, this thread looks relevant: Moving raid 5 drives to new nas from old failed nas

1 Like

Considering the WD My Cloud PR4100 is a new unit and Community knowledge is yet to develop then I believe it would be best to contact WD Support about this. You can do so over the phone or via E-mail.

Later on you could share your discoveries with the WD Community in order to assist other Users who have the same inquiries.

Based on what I heard over the phone from support, as long as the drives are placed in the new enclosure in the same order, it should work just fine.

Now to figure out what I want to do about upgrading the actual NAS hardware!

Hi @mdigirol

The new My Cloud Pro PR4100 is powered by an Intel Pentium N3710 Quad Core 1.6 GHz with boost up to 2.56 GHz and onboard Graphic card, used for the transcoding. It comes with 4 GB RAM (2 x 2 GB DDR3L SO-DIMMs) and can be encreased up to 16 GB RAM with 2 x 8 GB DDR3L Low Voltage 1.35 Volt SO-DIMMs 1600 MHz.

Thanks for the info @Joerg_A. This is one of the main reasons why I want to switch.

However, I must confirm with you… does this mean that the information I got from phone support is incorrect? The bolding in your message makes me concerned. So if you could confirm that I can put drives from the EX4100 into the PR4100 I would really appreciate it :slight_smile:

Thank you!

Hi @mdigirol

nothing to add, this is correct. We call it “RAID Move”. You only need to keep the order of drives. Put the drives into the PR4100 Enclosure and then power up the device. Wait until the OS has booted and check the IP address of the PR4100 shown in its display. Connect to this IP address and open the web interface of the PR4100, and “follow the instruction”.

It’s a pretty handsome and nice feature, I used it several times by myself.

1 Like

@mdigirol So did you purchase a PR4100 and migrate? I’m thinking of doing the exact same thing with my EX4100…another question, perhaps, is can you mix/match HDDs in the NAS? I currently have 4x4TB but I’d like to eventually upgrade them, perhaps one at a time. Is that doable?

Hi @mnarlock
yes, you can do it. But not perphaps one at a time, you have to replece them each single drive step by step. Otherweise your RAID will be lost if you are in RAID 5 mode.

replace the first drive, run the RAID rebuild
replace the second drive, runt the RAID rebuild
replace the third drive, runt the RAID rebuild
replace the fourth drive, runt the RAID rebuild

Now you can enhance the RAID to the new capacity.

Best practice is, to connect the My Cloud to an Uninterruptable Power Supply. If power cut would happen during the so called RAID grow at the end, it could end up in a catastrophy. UPS does not need to be huge, a 650 or 700 VA is more than enough if you connect only the My Cloud device. Even a battery-power-socket would help to prevent short power cuts.

Hi Jeorg,

got a question about so called ,RAID growth, Can it be done on two bays system as EX2100 which are configured as RAID 1 mode without loosing data?
I mean let´s say I have EX2100 with 2 x 4TB HDD in RAID 1 mode. I will buy two new 6 TB(or more) HDD and start as foĺlows:
a/ remove old 4TB HDD from slot 2
b/ put new 6TB into slot 2 and wait untill the unit rebuild the RAID 1
c/ remove old 4 TB HDD from slot 1
d/ b/ put new 6TB into slot 1 and wait untill the unit rebuild the RAID 1
e/ Enhance the space for RAID 1 so I can use all new 2x6 TB capacity - RAID growth.
Will this work ?

Please specify - where can I find the choice to ,enhance the space for RAID 1, sure without loosing data in DASH BOARD ? I´m realy worry that after I will choose some ,RAID growth, the unit will formate the HDD and wipe pretty much everything …


Hi, I know this thread has been idle for some time. I too have an EX2100 and thinking of upgrading to the PR4100. What is the best way to transfer this data over to the PR4100 (both NAS have their own respective disks, so no disk swapping etc.). Thanks so much.

Hi there, I think I mixed up with the drive orders, how do I tell which one is which?

Hi mdigirol ,

Well, you can switch from EX4100 to PR4100 without any loss of data. However, you need to keep the order of the drives. Make sure while putting the drives in PR4100 enclosure, device should be turned off. Then, turn on the device and you will be able to use the device properly.

Thank You!

Will this work for an EX4 to PR4100 as well? I have an EX4 that everytime I power it down it will not restore a allow me access. It reconnects to its assigned IP address and looks to be in a “steady state”, but I cannot access it.

I would like to simply move the drives into an upgraded enclosure, such as the PR4100, but I’m concerned about losing the data on the drives.

Will this work for an EX4 to PR4100 as well? I have an EX4 that everytime I power it down it will not restore a allow me access. It reconnects to its assigned IP address and looks to be in a “steady state”, but I cannot access it.

I would like to simply move the drives into an upgraded enclosure, such as the PR4100, but I’m concerned about losing the data on the drives.

I have the same question! Does this “RAID Move” feature also work when migrating from an EX4 to a PR4100?

I know this post is a few years old now, but I’m looking for additional confirmation on doing a drive swap. My EX4100 is set up in JBOD mode, can I swap the drives into the PR4100 without any data loss?

Very curious on this one. . . . reading the forums I was under the distinct impression that this would NOT work.
However. . .this thread gives me pause.

See this: https://support.wdc.com/knowledgebase/answer.aspx?ID=17087&lang=en

Further, this implies it should work: http://wdc.custhelp.com/app/answers/detail/a_id/22077/~/raid-volume-not-seen-(no-raid-roaming)-when-moving-hard-drives-from-a-my-cloud

There may be good reading material in here: https://support.wdc.com/knowledgebase/answer.aspx?ID=19562&lang=en

My view: One of the things that keeps me up at night is “What do I do if my NAS motherboard fails?”. I kind of thought it was game over. I now keep a backup of data on a hard drive at work (backup refreshed monthly). In part, I do this because of uncertainty I see on the boards here. In part, because a good lightning strike, or fire will take out the motherboard and drives in one fell swoop. This thread makes me feel better.

If I was upgrading boxes. . . I would not start the effort without a fresh backup on an independent device. I would also be inclined to have the new NAS on a UPS while critical drive rebuild steps was occurring.

Call me paranoid. But then again, anyone running a raid setup has to be at least a little paranoid. Why not go all the way :slight_smile:

Thanks for the links. Unfortunately they all seem to apply to RAID, not JBOD.

Well it doesn’t matter, I won’t be swapping the drives after all. The new NAS showed up today and imagine my surprise: instead of WD drop shipping the 16GB I ordered off eBay, I was sent a 24TB!


That is a great GroundHog Day present.