12-18-2025, 06:37 PM
No need to apologise, it is a very common question with new Terramaster buyers. The F4 425 does not come with TOS 6 pre installed in the way a router comes pre configured. When you first power it on with your own drives inside, the NAS will prompt you to download and install TOS onto those drives. Terramaster stores the operating system on small system partitions that live on each drive in the array.
So you do not need to buy a separate SSD just for the OS. The three hard drives you already ordered are enough to get the system running. Once TOS is installed, the space taken by the system partitions is tiny compared to the full capacity of the drives. Later on, if you want to add SSDs for cache, you can do that without reinstalling the OS.
If you would still prefer to keep the OS off the main storage pool, you can add a small SATA SSD and install TOS onto that, but it is not necessary and it does not give a performance advantage. Most users just install straight onto the HDDs and use their SSDs later for cache.
So you do not need to buy a separate SSD just for the OS. The three hard drives you already ordered are enough to get the system running. Once TOS is installed, the space taken by the system partitions is tiny compared to the full capacity of the drives. Later on, if you want to add SSDs for cache, you can do that without reinstalling the OS.
If you would still prefer to keep the OS off the main storage pool, you can add a small SATA SSD and install TOS onto that, but it is not necessary and it does not give a performance advantage. Most users just install straight onto the HDDs and use their SSDs later for cache.