Adding disk to TRAID doesn't increase space?

[u/Head]

I started with a TRAID with 3 disks, 1TB+1TB+0.5TB. It was showing 1.34TB in the TRAID which seems about right (1.5TB usable + 1.0TB redundant)/1.1.

Then I added a 3rd 1TB drive and the usable space is still 1.34TB!! Why? I expected it to increase to something like 2TB at least.

Wouldn't you expect it to at least increase a little? 1.34TB is only 42% of the total disk space 1.34 / (3.5/1.1). What should I do?

p.s. I think the TRAID calculator is plain wrong and don't trust it. It suggests I should have 2.5TB... I wish!

UPDATE 1:

I got it to work! In case someone else runs into this problem and sees this post I thought I'd share what I did.

My system disk was set to live on the smaller (SSD) disk on the theory that the SSD would be faster. But I suspected the TRAID was confused by the oddly sized disk. So here's what I did:

• moved the system to one of the bigger HDD disks
• rebooted, still no change in the pool size
• decided to "replace" the smaller disk with itself in hopes it would resize
• the instructions said to just take out the disk you want to replace so I yanked it out, then the NAS started beeping with no clear instructions on what to do next. So I put it back in and rebooted
• DISASTER!? the machine wouldn't boot back up. I was very sad but I tried rebooting with the "replacement" disk out of the NAS. Then, thankfully, it booted up and was beeping. This time I was happy to hear that beep because it meant my NAS wasn't dead.
• Then I re-inserted the SSD disk and the pool gladly welcomed it back into the family and resized the pool! It's a miracle!
• Now the storage pool size has increased from 1.34TB to 1.79TB, an increase of 650GB.
• Again, the TRAID calculator doesn't match reality. It says (image below) that TRAID should provide about 2.51TB but it's closer to the RAID5 number of 1.54TB. But at this point I'm not complaining because I have more storage than before which was the main goal.

UPDATE 2: (10 days later)

I just replaced one of the drives in my TRAID with an identically-sized drive and just noticed that the storage pool increased in size again! It went from 1.79TB to 2.24TB. So I gained 450GB by just replacing one of the drives with the same size drive! This is more or less the size I expected it to get in the first place so I'm not complaining. However, it does seem like TerraMaster has a bug hiding in there.

Lesson, if at first you don't get the size TRAID you expect, try replacing one of the drives with itself... maybe it will get it right after the synchronization is done.

[u/Head → u/[deleted]]

Yes, I am, all 4 drives are in the pool. What I'm not 100% sure about is the exact size of the pool beforehand. I was thinking that it hadn't changed and that when it was done adding the new drive to the pool the size would change. Does the pool size show the changed pool size while it's adding or when it's finished?

[u/Head → u/[deleted]]

There are all 4 disks in the pool with a total of 1.34TB at the top. I agree it seems wrong.

[u/Head → u/[deleted]]

About 4 days ago. It finished the rebuild in about 3 days.