How many maximum gigabytes CDJ 2000nexus can read?

I've used 512gb externals so you should be fine upgrading.

I've used a 2TB drive, just remember the maximums are in the database capacity, not the storage capacity. ;)

What size WAV files do you use?
What USB's are these because my USB 3.0 is not working as follows:
I have recently bought two CDJ2000NEXUS and used a SanDisk 64GB USB 3.0 with the LAN cables connected via a switching hub. I recorded some of my vinyl to WAV at 24Bit 48KHz and imported them into recordbox, sorted out cue points etc. and about half an hour in of just normal mixing, when I pressed the top of the jog dial and then selected a point on the needle search strip, the player that had the usb in just froze and said now loading, and never loaded. I tried formatting the USB via my PC using 3rd party software, suggested by SanDisk technical help 3 times as suggested in an earlier post and synced it again in RB. It happens in whichever player the USB is in whether the LAN is connected via switching hub or direct to the other player. I have used two of the same USB's in player 1 and 2 at the same time and the screen freezes in both. For some strange reason whichever player the USB is not in, plays the frozen track with no problem over the LAN connected to the player with the USB stick in. I have tried it every which way I could and it still happens. I have been in touch with pioneer UK and they say they are waiting for Japan to send them some CDJ's to try and recreate what is happening. No news for two weeks now. I have had to use a SanDisk 32GB SDHC card instead and this seems to have sorted the problem. My only problem is, all my files are WAV files so I can only have a certain amount on the USB at any one time because they are obviously bigger files. It does the same thing on a HAMA 32GB USB 2.0 stick.