Hi guys,
I am currently running my homeserver with 2 TB disks in RAID-0. I am running out of space and I will soon migrate it to a RAID-5, throwing in an additional 2 TB drive (all the data on the current drives will be transferred somewhere else, so basically I'll be creating a RAID-5 array from scratch).

Eventually I will run out of space once again, and I'll have to expand the array.
I have found this guide that explains a simple way to expand a RAID-5 array, but I have a question about that: if I add another drive in such way, will I lose redundancy? If I understand correctly, RAID-5 calculates parity data that will allow it to run even if one of the 3 drives is broken, but what happens if you have more than 3 drives?

I experimented a little in a VM and it seems that it works fine, even disconnecting one (virtual) drive from the VM.

Thanks in advance for your help.

it does not matter how many drives you have in a raid 5, you can only lose 1 with the ability to recover and use that array in a degraded state... anything else and you done for...