Rename External drive

I have a NAS which has an external drive Crucial X9 attached to it as a back up of the NAS, i want to rename the Crucial X9 drive so it appears last on the list, will this cause any issues?

In general changing the volume name should make no difference. Only reason that I say in general is because there may be the rare program that actually looks at the volume label. As an example there is a program called free file sync it will let you reference the volume label rather than a drive letter for copying files. The reason for this is that sometimes you may have something like a thumb drive where the drive letter is subject to change. Referencing the volume label instead of a drive letter we no longer care if the drive letter changes. But again, this is exceedingly rare and if for some reason you find that it does cause a problem you can always change the volume label back again. But I change volume labels all the time and have never ever had it cause a single problem.

I think I'd try x9 Crucial. My NAS drive years ago used Z: at the first setup then any additional NAS drives added would work back up the alphabet, even today if I Map a new folder on the drive it will show as Y:. But the key is to Map a folder on the drive, not the drive itself.