Hello - And sorry if this is a very basic topic for most of you all.

My server (an HP) can only have 5 HDD's, so over the past years I have been upping the HDD sizes as needed and now had several older and smaller HDD's that I would like to find a way to use in the system. 

Is there a device that I can use to tie these drives into the system? 

I've researched, but as I am not really sure what I am looking for, I'm not really sure if I've found anything useful...

Thanks-

you could get an external esata enclosure, assuming you have esata that supports multipliers.  Otherwise could go with a usb.  You should be able to find an enclosures for 4 or 5 drives in a reasonable price range.

And then unRaid will see the drives as internal?

Thanks-

Does anyone have any brand suggestions?

Thanks-

USB not recommended for array or pool disks for several reasons. Port multipliers will impact performance on multidisk operations such as parity check and rebuilds.

Sorry...but what does that leave if not USB or SATA port multiplier?

External SAS, it also works with SATA devices.