TerraMaster Forum

I have a Terramaster F4-212 with 4 10tb drives that had been working well for over a year. Just yesterday it started a hard drive chatter that took some time to shut down. It seems that one of the drives may have come to the end of its life. The information I have on the Disk tab is an orange "Warning" message on HDD1 that says, "Disk read latency or S.M.A.R.T. anomolies detected. Please back up your data and check the disk as soon as possible." Underneath it posts the HDD size of 10tb, useage time of 9544 H, and disk temp of 36C / 96F with a warning about the S.M.A.R.T. info. Going to the S.M.A.R.T. info there are 3 lines in red:
ID5 Reallocated_Sector_Ct 100-100-10-40
ID197 Current_Pending_Sector 100-100-0-56
ID198 Offline_Uncorrectable 100-100-0-56

I do not know if that means the disk is repairable or if it is toast. If repairable, how would I do that? If not repairable, can I replace the 10tb with an 8tb I have which will rebuild the array? Or will I have to start all four disks all over again?

Generally speaking you cannot replace a raid member with a smaller drive. You would require an hdd at least as big as your current one or larger. {And, that means at least actual capacity. Not all 10TB disks are the same size.} Then you should be able to rebuild the array.

Arktander wrote: ↑16 Sep 2026, 21:47

Here are the direct answers to your questions regarding HDD1 and your TRAID array:

1. Is the disk repairable or toast?

It is toast (failing physically).

S.M.A.R.T. ID 5 (Reallocated Sector Count), ID 197 (Current Pending Sector Count), and ID 198 (Offline Uncorrectable) all registering errors indicate physical bad sectors on the disk platters. Software tools cannot fix physical media damage. This drive should be replaced as soon as possible.

Important: If you do not have an up-to-date backup of your critical files, please make one immediately while the array is still accessible.

2. Can you replace the 10TB drive with an 8TB drive?

No.

In RAID and TRAID configurations, any replacement drive must be equal to or larger than the drive being replaced (in this case, 10 TB or larger). The system cannot rebuild a 10 TB slice onto an 8 TB drive.

3. Do you have to start all four disks over again?

No, you do not need to start from scratch.

A 4-drive TRAID provides 1-disk fault tolerance. You can replace the faulty drive without destroying the existing pool:

• Power down the NAS, remove the damaged HDD1, and insert a healthy new drive with a capacity of ≥ 10 TB.

• Briefly press the power button to turn on the TNAS.

• Go to Storage Manager > Storage Pool > More > Repair Array > Select Disk > Confirm Settings, and wait until the array synchronization is complete.

Please let us know if you run into any issues during the rebuild.