TerraMaster Forum

Posted: **20 Nov 2025, 02:28**

I'm slowly getting my jumble of external drives migrated over to my new 4-bay TM NAS. I'm running TOS6 on it. I am looking to expand my TRAID array from 2 to 3 HDDs. It has a 12TB and 20TB drive in it with a storage pool set to max, which is 10.90TB.

When I go to expand the storage pool by adding a 20TB drive, the software shows I will go from 10.90TB to 18626.56 TB. This is a huge amount lower than the TRAID calculator (https://support.terra-master.com/raidca ... n/?lang=en) shows I should have, which should be 32TB of available space.

I'm not sure why the calculator is off by so much for how much space I should have and I specifically purchased this new drive expecting to have 32TB of space, so I'm not sure what is going on. Below are the screen shots of my current Storage Pool, the confirmation box showing if I add the third drive, the capacity is only 18TB, and the calculator showing I SHOULD have 32TB of available space.

Any help on this would be greatly appreciated. Thank you!

Posted: **20 Nov 2025, 09:54**

The situation you described is quite unusual, and we currently do not have enough information to identify the issue.
Please generate and download the system report package in TOS Desktop > Technical Support > Report an Issue, then download it and send it to our support email for inspection.
Technical Support Team: support(at)terra-master.com
Please include the URL of this forum post so we can identify you, dear customer.

Posted: **21 Nov 2025, 02:42**

I've submitted it. Thank you.

Posted: **21 Nov 2025, 11:38**

Your new 20T disk (sdc) appears to have been used on another system before and was formatted with partitions that are difficult to clean. Therefore, it cannot be successfully added to TRAID. Please manually clean its partitions using the Disk tool and then try again.

Code: Select all

sda1        8:1    0  285M  0 part  
└─sda       8:0    0 10.9T  0 disk  
sdb1        8:17   0  285M  0 part  
└─sdb       8:16   0 18.2T  0 disk  
sdc1        8:33   0  200M  0 part  
└─sdc       8:32   0 18.2T  0 disk  
sdc2        8:34   0 18.2T  0 part  
└─sdc       8:32   0 18.2T  0 disk  
md8         9:8    0  1.9G  0 raid1 [SWAP]
├─sda3      8:3    0  1.9G  0 part  
│ └─sda     8:0    0 10.9T  0 disk  
└─sdb3      8:19   0  1.9G  0 part  
  └─sdb     8:16   0 18.2T  0 disk  
md9         9:9    0  7.6G  0 raid1 /
├─sda2      8:2    0  7.6G  0 part  
│ └─sda     8:0    0 10.9T  0 disk  
└─sdb2      8:18   0  7.6G  0 part  
  └─sdb     8:16   0 18.2T  0 disk  
nbd0       43:0    0    0B  0 disk  
nbd1       43:32   0    0B  0 disk  
nbd2       43:64   0    0B  0 disk  
nbd3       43:96   0    0B  0 disk  
nbd4       43:128  0    0B  0 disk  
nbd5       43:160  0    0B  0 disk  
nbd6       43:192  0    0B  0 disk  
nbd7       43:224  0    0B  0 disk  
vg0-lv0   252:0    0 10.9T  0 lvm   /usr/local/@APP_CONFIG
│                                   /home
│                                   /Volume1
│                                   /var/subvols/8vEbTxkKvwa
└─md0       9:0    0 10.9T  0 raid1 
  ├─sda4    8:4    0 10.9T  0 part  
  │ └─sda   8:0    0 10.9T  0 disk  
  └─sdb4    8:20   0 10.9T  0 part  
    └─sdb   8:16   0 18.2T  0 disk

TerraMaster Forum

[Help] Calculator says I'll have 32TB free but Storage Pool says 18TB. Why?

[Help] Calculator says I'll have 32TB free but Storage Pool says 18TB. Why?

Re: [Help] Calculator says I'll have 32TB free but Storage Pool says 18TB. Why?

Re: [Help] Calculator says I'll have 32TB free but Storage Pool says 18TB. Why?

Re: [Help] Calculator says I'll have 32TB free but Storage Pool says 18TB. Why?