How to do single hard drive

[sretalla]

why at pool i can't create a new pool?

I suspect you didn't give the pool a name... you can't click create until you do that (and in your case also check the Force option since you're making a single disk stripe).

 

[DDD]

May I ask *why* you want to use just a single hard drive with FreeNAS? Understanding what you're after will help us assist you, or offer other alternatives that may be more suitable, sir.

I would also like to start with one small OS SSD Drive and another bigger 8TB SSD Drive for the Data. Because of the Price of the bigger SSD Drives and to save Power Consumption.
Downtime is not really important for me. I plan to have Backups of the Data on another NAS and external HDD Drives.
Do i have an benefit from 2 SSDs for data in relation to the data corruption, or it's the same like in 1 SSD drive setup?
That would be a reason for me to start with 2 data SSD drives nevertheless.