Increase storage on please!


Why is it so difficult to find this answer? I have the PR2100 and use this for a Plex server. I have 12tb in raid 1. I recently got a great deal on some 10tb red drives and want to install these into the NAS without losing any data.

Can I simply remove one of the current 6tb drives and replace with the 10tb drive? I understand I’d need to let this then copy files over but my concern is will it only allow 6tb partition or, when I then install the 2nd 10tb drive, will it recognize I now have 10tb avail in raid 1? Is this the best way to do the upgrade?


Yes the extra volume will become available after the 2nd drive has rebuild the RAID array.


Have they come up with a term for “fear of losing digital data” yet? I have that in a big way. I can have multiple backups of everything and still have anxiety about it.

Thank you for your help.


So, I upgraded the drives and all data copied over to both. I’m now showing a healthy volume on both but it is still only using 6tb of each for the volume. I want to add the additional 4tb on each drive to the volume. Is there a way to do this without deleting the volume? I would prefer to just add the additional storage space to the existing volume.


I believe there is a button somewhere in the web GUI to resize your RAID array now.

If there is not, use SSH and type this

resize2fs -p /dev/md1

or when that complains, use a force resize.

resize2fs -fp /dev/md1

The script uses the same command.
If it still would fail, please provide output of

df -h


I took another look and sure enough there was an option (hidden in my opinion) to expand the volume. It was under change raid which was an area I didn’t want to venture but chanced it.

Thank you for your input. Looks like I’m reclaiming all the additional space now. Why it takes 10 hours to expand to the full drive is beyond me though.


I have used this technique of swapping one disk, wait until stable, swap the other, wait until stable and reboot on a very old and obsolete Iomega IX-200, and it worked fine. I am about to try upgrading my PR2100 from 2x3TB RAID 1 to 2x8TB RAID1. It should work, and this thread tells me that I can. (I also put in a direct request to WDC support, THEN found this thread. All 3TB and 8TB drives are WDC Red.

Is there any reason that I should not upgrade my disk size on my PR2100 the “easy” way, as I note above?


I did end up upgrading my PR2100 to 2 x 10TB RAID 1 and it was fairly simple. I chose the least risky option which was to pull the drives and use as my backup while I installed the new drives. From there it was just copying my files back onto the NAS.

Thank you for your reply though. I couldn’t believe this NOOB question wasn’t easily answered somewhere but I searched everywhere for the answer to “will adding a new drive erase my files?” and couldn’t seem to find it. Being very new to the NAS thing I was worried.

Best wishes!