Expanding TRAID Pool: 24 TB Drive with Existing 18 TB Drives

[AndroidBOX]

Hi there,

I have a TerraMaster F4-423 with 3×18 TB HDDs already installed and configured as a single pool.
The system is set up using the BTRFS file system and TRAID, and I believe the pool is configured with single-drive parity, as I originally started with only two drives when I first set up the NAS.

I wasn't able to get another 18 TB drive, so I opted for a 24 TB HDD instead.

Now, I'd like to add the 24 TB drive to the existing pool (which is why I chose TRAID back then) to expand the usable storage.
Can I simply add the larger 24 TB drive to the pool, let it synchronize, and expect everything to work properly—perhaps not gaining the full 24 TB, but instead around 18 TB of usable space, as I assume?

Thanks to anyone taking the time to answer and help!

(Apologies if I'm confusing "pool" and "volume"—I'm not the most advanced NAS user.)

[ed]

You’re on the right track with your understanding of TRAID and BTRFS in your TerraMaster F4-423 NAS.

Here’s what to consider when adding a 24TB drive to your existing 18TB drives:
TRAID and Drive Size Compatibility:
TRAID (TerraMaster’s proprietary RAID-like technology) allows for the expansion of storage pools with larger drives. However, the way TRAID works is that the pool will only utilize the smallest drive size across the array for parity and data distribution.
So, when you add the 24TB drive, it will essentially be treated as 18TB (since it’s larger than the other drives) for the purpose of your pool. The extra 6TB on the 24TB drive will be unused until you either add another drive of at least the same size or fully rebuild your pool.

Adding the Larger Drive:
You can add the 24TB drive to your existing pool without issues. The process will likely involve the following steps:

Install the 24TB drive into an available bay.

The system will start synchronizing to integrate the new drive into the pool. It will use the same 18TB limit for the pool initially.

After the synchronization completes, you should be able to see the additional capacity for future use once another larger drive is added, or when the existing smaller drives are replaced.

Full Use of the 24TB Drive:
If you want to make full use of the 24TB capacity, you would need to replace one of the 18TB drives with another 24TB drive. This way, your TRAID pool will eventually be able to recognize the full capacity of the 24TB drives, and the extra space will be fully utilized.

Important Considerations:

Backup: Always ensure your data is backed up before performing such operations, especially when expanding a storage pool.

TRAID Parity: Because you're using single-drive parity, there's a risk that if one drive fails during the expansion process, you might lose data. If possible, consider using dual parity for greater protection.

TRAID Rebuild: After adding the larger drive, the system may need to rebuild the pool, so be prepared for a longer process depending on the amount of data.