I was under the assumption (apart from restrictions due to old operating systems not being able to read large drives) that as long as a hard drive was of the same type as what is available for the computer (e.g. if the computer has IDE, you can plug any IDE drive into it, or if it has SATA that you can plug any SATA into it). However recently I was going to purchase a relatively old computer and wanted put a couple of 4TB drives on it because it will be used to store surveillance videos, so I need very little actual computing power, but lots of storage. However the sales representative told me that a 4TB drive wouldn't work with that server. When I checked the specs, it says:
Internal storage capacity of up to 1.5TB (2 x 750GB Hot Plug 3.5" SATA hard drives), 1 TB (2 x 500 Non-Hot Plug SATA hard drives) or 600GB (2 x 300GB Hot Plug 3.5" SAS hard drives)
Is this because there is some actual hardware restriction putting a drive larger than this on the server, and if so, what would cause this and what would happen if you did put a larger drive on the server?
Or, is this because those were the largest drives of those types that existed at that time, so that's what they used in the specs, but it is actually possible to put any drive that can physically be plugged in (e.g. 2 x 4TB 3.5" SATA drives) and they will function correctly?
If you use the built-in SATA ports, you'll be limited to 2TB by the Intel 5000X chipset.
You could put a SATA or SAS PCIe card in the server that supports larger drives.
Some operating systems and file systems have 2TB limits. Some BIOS also have limitations as to how large of a drive they can detect.
So yes it is absolutely possible that it won't work.
If this is a Windows machine then the following article is useful:
https://support.microsoft.com/en-us/kb/2581408
More than likely the drive will work. It's likely that 1.5TB was just the largest part number that HP created at the time of writing the documentation for that server.