what is the maximum size drive that a nsa320 will accept

rray,

As large as you want as a non-boot drive. But to use HDD that is larger than 2 TB as the boot drive, you need to install the new u-boot (as I mentioned on the other thread). The stock/old u-boot will likely accept only up to 2TB.

-bodhi
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that's on my to do list
thanks

I know @bohdi isn't a fan of them but I have had some really good luck with hybrid MBR/GPT partition tables to allow older devices that boot from disk to use large drives without replacing u-boot.

I've actually recently been testing some old orion5x devices from ~2007 with 4TB drives with surprisingly good results.

I'm still working on the documentation but this includes the gdisk output used to convert an MBR to hybrid MBR/GPT that works with ancient versions of uboot as well as a link to a really good article that explains how hybrid partition tables work:

https://github.com/1000001101000/Debian_on_Buffalo/wiki/Alternate-install-method-via-debootstrap-script#Post_install_steps