Dual ex4100 mirroring setup needed?

So we have one ex4100 now with 4 drives each 4tb with striping so we have 12tb capacity. I have one share that is 5.7TB and have been backing it up to a 8TB USB drive. But now the backup is failing and all I can tell is the dreaded “Backup Failed” - Backup failed. Please check your system settings. Backup Type Synchronize
Current Version

Lots of searching shows it might be a known issue with USB backups and the total backup being large. So I thought this is not good that this is still a “known issue” with no fix but now might be the time to get a second one to remote back up to or clone it.

Anyone using a second ex4100 for back up or I would like to just run it as a remote clone so that both have exact copies of the data for redundancy.

See the dedicated subforum for the EX Series where users more familiar with that device may be able to assist. This subforum (My Cloud) generally covers the single bay/single drive My Cloud unit.

My Cloud EX Series