Hi all, long time listener first time caller,

I have a WD PR4100, old equipment but it suits my needs, I maxed out the ram when I first bought it 5 years ago and it has 4 drive bays. Right now I have four 4TB WD Red Pro/Premium drives inside in a RAID1 setup. One of the drives is more recent and the other 3 are from when I bought the PR4100 5 years ago.

It is time for me to replace the drives, one started failing awhile back and that is why it was replaced, but in anticipation of the other 3 failing eventually I would like to upgrade them all and to take this opportunity to replace them with higher capacity drives.

First question, is there an upper limit for capacity on the PR4100 and can I just drop new 20tb+ drives in there and expect them to work?

Second question, do I replace them one at a time and in doing so would the system rebuild the RAID 1 setup or is there a better way?

This is for local backups and a self-hosted media library, not commercial or professional use.

I am not looking to build a new NAS system right now as the PR4100 is working as intended without much hassle but in a year or so I may need a more complex and professional NAS/server depending on if I get back into video production more fully.

Thank you for your time and for everyone posting and providing help in this community.

  • @NyxonOPEnglish
    1•3 months ago

    Thank you for your thorough response!

    I figured there wouldn’t be an upper limit but I’ve been burned before in the past with trying to use too big of a drive in various applications over the past 3 decades of computer use so I wanted to be sure before dropping a lot of money on new high capacity drives for the NAS.

    When I replaced the one drive a few months ago I just removed the faulty drive from the NAS and slotted in the new drive in its place and the NAS copied everything and was up in running again in a few days. It was only 4TB but it took awhile. I know it should be able to if I replace like for like sized drives but I wasn’t sure how it would be have if I start replacing 4TB drives with 20tb drives.

    I do have a drive cloner already, buried in an old tech box in the garage that I could use but it is several years old (6 maybe?) so I am sure it isn’t as fast a a newer one. Maybe I will pick up one or two of the ones you suggested to speed the process along.

    • @[email protected]English
      2•3 months ago

      I don’t know that a newer drive cloner will necessarily be faster. Personally, if I’d successfully used the one I already have and wasn’t concerned about it having been damaged (mainly due to heat or moisture) then I would use it instead. If it might be damaged or had given me issues, I’d get a new one.

      After replacing all of the drives there is something you’ll need to do to tell it to use their full capacity. From reading an answer to this post, it looks like what you’ll need to do is to select “Change RAID Mode,” then keep RAID 1 selected, keep the same disks, and then on the next screen move the slider to use the drives’ full capacities.

      • @NyxonOPEnglish
        1•3 months ago

        Ah ha! Thank you, this was one of my worries with increasing the capacity, I was worried that even after replacing the 4TB drives with larger capacity drives that the new drives would still only be limited to the lower capacity partitions. I wasn’t sure if there was a way to increase them.

        My work around for this was to back up all the data on the NAS currently (only ~7.2TB) onto an external drive. Put the new larger capacity drives into the NAS, format them properly and setup the RAID as needed and then transfer the data back onto the new fresh larger capacity drives in the NAS from the external drive.