Just got a Mi Box to replace my current raspberry pi kodi box, Can i use the external hdd that i'm using with the RPI, without formatting it first? The hard drive is formatted to exFAT. Also, is there any support for samba? or anything like that, so i can access the hdd from my pc?
exFAT is supported but you should bear in mind that AndroidTV is Linux at its core and so since exFAT is a relatively new file system with all new patents the support for it has lagged behind older file systems such as NTFS or FAT, which means you'll want to be careful unmounting the drive before disconnecting it to avoid issues with file corruption. Presumably you can fix it with your Windows box but depending on the size of the drive that can be a pain in the ass.
Also you want to be careful when plugging it in because the AndroidTV OS will ask you every time if you want to format the drive or mount it. Always check what you're highlighting as a selection before hammering the center button.
That having been said it's what I've been using on my Dad's MiBox for Kodi and it seems to work well enough.