Lion to el Capitan

[Pheesegas]

I have My Book Studio for mac.Set up on OSX LION.Will it just swap into el Capitan,or will it need to be reformatted? I need advice please.

[Trancer]

It should not need to be formatted if your unit is currently formatted in a supported configuration such as HFS+.

[Barrie_Tumbridge]

I have had two drives used from Mountain Lion the El Capitain and have not had to change anything.

[Pheesegas]

Thanks for your help