Question Spanned Volume Error

[Olinee]

I'm following this YT video (How To Combine Two Hard Drives To One) but when I go to confirm the New Spanned Volume... I'm met with this error message: "There is not enough space available on the disk(s) to complete this operation." Both 250GB SSD drives are clean with nothing on them. What am I doing wrong?

 

[Andrei N]

So first of all you need to post the OS.
Second, you need to post the screenshots from the procees as attached:
Third, a spanned volume has absolutely no benefit over 2 individual partitions unless you are going to write files larger than 1 partition can handle.

https://imgur.com/a/IpTJA6w

View: https://imgur.com/a/IpTJA6w