Maybe the permissions set by the mount entry for the 8TB drive do not allow it to be exported.
I think some people would say that exFAT is a bad idea for an 8TB drive and recommend ext4.
I'd certainly advice against exFAT (or FAT32) on an 8TB drive. Because of the way those work teh bigger the partition the more space you waste.
But I'd advise against NTFS too.
The only reason for using either on a Linux box is if you need to physically connect them to a Windows box. If you don't you should use a Linux native FS.
@OP:
Network clients using NFS and Samba don't know or care what the filesystem on the server is. The use whatever the protocol presents to them.
Definitely check those mount options on both client and server.
You also don't need both lines in your exports file. The second one should be enough.
Boot time mounts are handled by systemd so check the journal.
If you don't already do so, reboot the 3B when you change which drive is mounted on the 4B. Stale info could be hanging around on that end.
Without the error message(s) I can't suggest anything more concrete. Sorry.
Statistics: Posted by thagrol — Thu Jan 15, 2026 6:45 pm