Linux Questions

I use an older HP thin client PC with a 4TB solid state drive as an SFTP file server using vsftpd, but if you are local only then an SMB server using samba would probably be fine. I use SFTP because I wanted something a bit more secure which I can port-forward with my router on a random higher-numbered port for remote access.

I mostly taught myself how to do this by looking at guides originally meant for the raspberry pi, but there is nothing different about running these same programs on Debian or the like. Personally, I would not recommend a raspbery pi for a large file server, as they do not natively support SSDs without additional hardware which will make the price significantly higher and less self-contained than a used, older-gen thin-client PC which can be had for relatively low cost on places like ebay (though they do make some fairly high capacity micro SD cards these days).

Hardware-wise, generally these types of servers are not CPU intensive, nor do they require any particularly high amount of RAM, so an older-gen or lower power CPU can often work fine, but you should probably make sure to get something with at least gigabit ethernet speeds, as a 100Mbit connection on, say, a raspberry pi 3 or older will be very slow for transferring large files.